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Driving With BiOptic Telescopic Lens Systems


A presentation  by Charles P. Huss, C.O.M.S


This paper was presented at The Eye and The Auto International Forum in June 2001 at the Daimler Chrysler Technology Center in Auburn Hills MI. The Eye and The Auto is a research project of the Detroit Institute of Ophthalmology (DIO). Thirty-two of the world's leading authorities in vision and vision related research were brought to the metropolitan area of Detroit as guests of the DIO to discuss the relationship of vision and safe operation of motorized vehicles.  For more information, go to http://www.eyeson.org and click-on The Eye and The Auto, under Research. The proceedings are available for purchase.


Index to the Presentation



        0.  The Presentation

        1.  What is a BiOptic telescopic lens system (BTLS)?

        2.  What benefits can a visually impaired driver derive from the use of a BTLS?

        3.  Using the BTLS during the driving task

        4.  Introducing a visually impaired person to the proper use of the BTLS for driving.

       5.  Major misconceptions about driving with a BTLS.

       6.  Who is a good candidate for driving with a BTLS?

       7.  The most common types, styles and power of BTLS used in driving

       8.  How to improve and better regulate driving with a BTLS.

       9.  Concluding Remarks

      10.  Questions or Concerns and Responses

      11.  SLIDES


To Find Out More...

0.) The Presentation


Currently (6/2001) there are 31 States that issue driver licenses to select low vision individuals who use BiOptic telescopic lens systems. Collectively there are over 4,000 such drivers in the United States.  Despite the fact that such licensing practices have existed in many of these States for 10 - 30 years, some individuals still question, and perhaps rightfully so, the validity and use of such devices for driving.  The intent of my presentation is to educate and provide insight as to what driving with BiOptic telescopic lens systems is all about starting with:

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1) What is a BiOptic telescopic lens system?

A BiOptic telescopic lens system (abbreviated BTLS) is a combination two(2) lens optical system consisting of a standard or conventional pair of carrier lenses (slide 1); and a miniature telescopic lens unit(s) mounted permanently at a 10 degree angle to the upper or superior portion of the carrier lens (slide 2).

These devices (slide 3), which are mounted in a sturdy frame presenting spring loaded hinges and adjustable nose pads, are prescription in nature and available through an optometrist or ophthalmologist who specializes in clinical low vision.

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2) What benefits can a visually impaired driver derive from the use of a BTLS?

Once trained in the proper and appropriate use of a BTLS, a visually impaired driver is able to detect and identify detail (slide 4), color (slide 5) and/or movement of distantly positioned objects or forms more effectively and confidently.

When using the latter device, the visually impaired driver is able to increase his/her " margin of safety " from critical objects or forms present within, along side of , or approaching their intended path of travel (slide 6).

Margin of safety is defined as the time or distance needed by the BTLS user to process, predict and decide whether or not to react to such critical objects or conditions.

Driver education professionals define critical objects or conditions as any object or condition which can be predicted to influence or require drivers to adjust their vehicle's speed and/or lane position.. Examples include: roadway characteristics, other road users and traffic control devices.

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3) In what manner, under what conditions and how often would a visually impaired driver use their BTLS during the driving task?

Persons using a BTLS look through the lower carrier lens (slide 7) for general viewing purposes (for instance, for gross object awareness or orientation to their driving environment); and through the telescopic lens unit for more distant detail/color/activity recognition as previously indicated during the driving task (slide 8).

Movement into and out of the telescopic or magnifying portion of the device is accomplished through a simple synchronized downward-upward head and eye movement.

The upper limit of one's pupil should be parallel or in line with the lower portion of the ocular lens end of the telescopic unit during carrier lens viewing.

This offers the best or optimal viewing through the carrier lens and minimal fixation time , going from unmagnified to magnified viewing and back.

Vertical spotting through one's BTLS is recommended only on straight or relatively straight stretches of roadway; and then only in the absence of critical objects or forms within the space cushion surrounding the BTLS user's vehicle. The telescopic portion of this lens system is used for extremely short periods of time (one second or less per fixation ).

Because of its physical location on the carrier lens (above one's normal line of sight or viewing) the telescopic portion of the device will not obstruct the other 95-97 per cent of normal non- magnified viewing accomplished through the larger carrier lens while driving.

The frequency of use of the BTLS is dependent upon the user's ever-changing driving environment , his/her familiarity to the latter, the dynamics of driving environment (slide 9), and an individual's functional vision abilities related to awareness acuity* v. identification acuity* v. preferred viewing distance* (with and without the BTLS).

If the above-mentioned functional visual acuity terms are new to your vocabulary, permit me to define what each means briefly:

*Awareness acuity - refers to the furthest distance at which the presence of any form is first detected (for ex. shapes against the sky, blobs or blurs of color indistinguishable as specific objects);

*Identification acuity - refers the furthest possible distance at which a detected form is first correctly identified (for ex. that red blob is beginning to look like a car);

*Preferred viewing distance - refers to the most comfortable distance for identifying a detected form (for ex. " I am definitely sure now that object is a car ")

Definitions taken from Foundations of Orientation and Mobility, Weiner and Blasch, Eds.,1996 from chapter entitled Low Vision Mobility by Duane K Geruschat and Audrey J. Smith.

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4) How do you go about introducing a visually impaired person to the proper and appropriate use of the BTLS for driving?

An easy and effective way to familiarize a visually impaired person to the proper and appropriate use of the BTLS for driving is as follows:

  1. Locate a straight stretch of paved roadway at least 100 -150 yards in length with minimal to no moving traffic (preferably a two-lane, 2-way roadway with double solid yellow pavement markings and white edge lines);
  2. Have student position self approximately 2-3 feet to the right of the yellow pavement markings (corresponding to the position that he/she would assume when driving on this type of roadway, slide 10);
  3. Have instructor position self in an identical position as student is , then turn and face student at a typical conversational distance (2-3 feet apart);
  4. With head mounted 49MHz transceivers and BTLS in place on student and instructor (slide 11), have instructor explain to student that he/she will walk off a 10 yard distance from the student , positioning self mid- way between pavement markings and edge line on same side of roadway as student is standing, and then turn and face the student;

  5. At this first 10 yard distance from one another, instructor will explain how to use the BTLS via a basic vertical spotting technique, and then request that the student practice reinforcing the latter 5 times slowly;
  7. At this same distance, instructor will introduce student to the optical and non-optical characteristics of the BTLS (which is the center of controversy between opponents and proponents of these devices for driving) via hands-on demonstration and feedback.  The latter will include but not be limited to:

  8. - Differences in image size v. distance (slide 12)

    - Fixation time

    - Restricted field of view (slide 13)

    - Ring/rectangular scotoma (slides 14-15)

    - Apparent movement of objects in direction opposite to head movement

    - Reference point maintenance (magnified v. unmagnified field, (slide 16)

    - Linear distance relationships between instructor and student under magnified v. non-magnified viewing conditions (stating the actual v. apparent distances measured in yards and feet from a prepared distance equivalent sheet);

    - This is where the aforementioned functional vision abilities of awareness acuity, identification acuity and preferred viewing distance come into play under magnified v. non-magnified viewing conditions.

  9. All of the above exercises and hands-on experiences are then repeated at increasingly 10 yards increments (out to 100 yards).

By lesson's end , many of our past students have stated that for one of the first times in their lives, they finally have some concrete idea of how they compare or match up to a normally sighted person in terms of what objects, forms or activity they can detect and identify under magnified v. unmagnified conditions, at different distances, natural lighting and weather conditions.

Students also find themselves capable of using their respective BTLS as an of effective vertical spotting device (needing only .5 of a second per fixation) after only 1-2 hours training.

The latter then sets the stage for continued BTLS reinforcement under dynamic on-road conditions; first as a passenger-in-car, then while driving.

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5) What are some of the major misconceptions about driving with a BTLS?

Misconception #1 A BTLS is the " cure all " to being a safe low vision driver.

Misconception #2:  Low vision drivers need not use a BTLS in familiar driving environments (slide 17).

Misconception #3:  BTLS are used continuously v. intermittently during driving; and as a result, a BTLS user drives blind to traffic (slide 18).

Misconception #4: Approach magnification, or moving closer to an object to see it, is safer than using a BTLS because the field of vision and depth perception are not affected and there is no need to change fixation (slide 19).

Misconception #5: The only way we can determine the safety of BTLS drivers is over prolonged periods of time and field experience.

Misconception #6: Legally-blind BTLS drivers have higher at-fault accident and violation rates than BTLS drivers with milder forms of central visual acuity loss.

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6) What type of visually impaired driver would likely make a good candidate for driving with a BTLS?

From my personal experiences of working directly with individuals who participated in our WV Low Vision Driving Study, 1985-1995, and from other authors (including but not limited to: William Feinbloom, OD, Dennis Kelleher, Ed.D., Ian Bailey, OD, and Randy Jose, OD), I would say the following characteristics best describe the type of individual who would be an appropriate candidate for driving with a BTLS (slide 20):

  • Pre-driver readiness and awareness skills (list of skill areas available by contacting author)
  •  Stable ocular condition, preferably congenital or long term in nature
  • Visual acuity between 20/50 and 20/200 inclusive with best standard or conventional correction; (slide 21
  • Full bilateral field of view and absent of any large scotomas (if monocular, at least 120 degrees horizontally and 80 degrees vertically, slide 22)
  • Improved visual acuity via telescopic magnification to meet a State's visual acuity screening standard for driver licensing (slides 23-25)
  • Non-photophobic 
  • Good glare recovery skills 
  • Good contrast sensitivity skills  
  • Good color vision 
  • Normal head, neck and eye motility 
  • Normal bilateral hearing 
  • Average to above-average intelligence 
  • Free of visual attention deficits
  • Highly motivated, dedicated, hard working, goal orientated 
  • Non-aggressive, yet assertive 
  • Non-impulsive 
  • Able to accept objective criticism 
  • Emotionally stable 
  • Past participation in sports or recreational activities that require eye-lead and head and eye scanning abilities (for example: basketball, baseball, racket-ball, bicycling, roller-blading, skateboarding, downhill skiing).

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7) What are some of the most common types, styles and power of BTLS used in driving?

The BiOptic telescopic lens systems used in the WV Low Vision Driving Study, were designed and manufactured by Designs for Vision, Inc. (DVI), Ronkonkoma, NY and Edward's Optical Corporation (BITA), Virginia Beach, VA. (slides 26-30)

The range of magnification allowed for use by participants was 2.2X - 4.0X.. In most instances, the strength (expressed in X- powers of magnification) of the BTLS prescribed for our graduates was obtained by dividing the carrier lens acuity level by 20/40, the arbitrarily set visual acuity protocol for our study. 20/40 was the visual acuity screening standard in place in WV for an unrestricted driver's license at the onset of our study.


    · 7 individuals were fitted with the DVI 2.2X BIO II (4 OD, 3 OS) 

    · 2 individuals were fitted with the DVI 2.2 X BIO II Eagle Eye (1OS, 1 OU) 

    · 6 individuals were fitted with the DVI 3.0 X BIO I (3 OD, 2 OS, 1OU) 

    · 5 individuals were fitted with the 3.0 X BITA (3 OD, 2 OS) 

    · 10 individuals were fitted with the 4.0 X DVI BIO I (8 OD, 1OS, 1OU) 

    · 2 individuals were fitted with the DVI 4.0X EFP (1OD, 1OS)

Other prescription BTLS that have been fitted and dispensed to visually impaired drivers of other States include:

    · Ocutech Inc.'s 3X-4X Visual Enhancing System (VES-K) and 3X VES- MINI (slides 31-33); 

    · Optical Designs, Inc. 4X Behind-The-Lens Telescope (slide 34); 

    · M-Tech Optics Corporation 4X M-Lens SYSTEM (slide 35).

Of the 32 individuals who completed our program of instruction satisfactorily, 28 graduates were fitted and dispensed BTLS presenting monocular mounted telescopic lens units; while the 4 other remaining graduates were fitted and dispensed BTLS presenting binocular mounted telescopic lens units.

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8) What can be done to improve and better regulate driving with a BTLS?

  1. Mandate formalized low vision driver education training and assessment (slides 36 to 39 , 40 to 45 and 46 to 49/50);
  2. Provide staff in-service training related to driving with low vision and BTLS to driver examiners who will be assigned to test BTLS candidates;
  3. Require standardized passenger-in-car testing and actual on-road testing by trained driver license examiners for all applicants seeking driver licensure using BTLS;
  4. Test and allow competency-based driving privileges;
  5. Require periodic eye and driving re-examinations;
  6. Encourage States to keep and maintain driving records of BTLS drivers;
  7. Use a certified driver rehabilitation specialist (C.D.R.S.) and/or certified orientation and mobility specialist (C.O.M.S.), who has experience in evaluating and training BTLS drivers, as a liaison to State Department of Motor Vehicles Medical/Vision Advisory Boards.

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9) Concluding Remarks

In conclusion, learning how to use a BTLS properly and appropriately is just one aspect of formalized low vision driver education training and assessment. (please see LOW VISION DRIVER EDUCATION TRAININGa published article by Charles P. Huss).

As student learns and gains experience with all the physical, mental and social skills required of the driving task, instruction moves from a spoon-fed approach to that requiring independent decision making.

The latter then permits the introduction of a standardized objective type of on-road driving assessment, including the correct use of one's BTLS under real-world driving conditions.

Such standardized on-road assessments can and have been used to monitor a student's progress and advise instructors and student what areas of instruction need to be emphasized during the remaining weeks of training, prior to consideration of application for driver licensure.

Once again, thank you for this opportunity !!! With time remaining, I will address any questions or concerns that faculty or attendees may have concerning " Driving with BiOptic telescopic lens systems".

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10) Questions or Concerns and Responses

Question: I realize that it may differ from individual to individual, but can you give us a basic idea of how much training an individual should have in order to drive with BiOptics?

Answer: In West Virginia, we offered an individualized, competency based, concurrent type of low vision driver training program extending over 6-8 weeks. Normally a student would receive: 30 hours of classroom instruction, 40 hours of passenger-in-car experiences (a combination of environmental awareness and hazard perception skill training, with their prescription BiOptic telescopic lens system in place), and up to 50 hours of behind -the-wheel training if needed.

Concern: (Phillip Hessburg, M.D.) I wanted this paper delivered because I'm not sure I believe this or don't believe this. I think what it proves is that most people do most of their driving at about 20/200 or are able to. I'm not sure that what we're doing with this use of the BiOptic) isn't primarily reading street signs and determining whether a traffic signal is red or green.

I am also not certain whether or not, as ophthalmologists, we should be recommending that we refer visually impaired persons to Doctor Mogk, M.D., Ophthalmologist for evaluation, fitting and prescription of BiOptic telescopic lens systems? Until I know that I am not doing a disservice to such low vision patients, I'm am not going to recommend it. So maybe over the course of the next two days, you're going to convince me that I am not doing a disservice to people. My purpose is to increase the mobility and the independence of elderly people, but I'm not positive yet, nor have you convinced me, that the way to do it is with BiOptic telescopic lens systems.  [For more information about fitting a BiOptic, please click here].

Dr. Lylas Mogk, do you want to comment? Are you prescribing them, or should we be?

Response and Question ( by Lylas Mogk, M.D.): No. I have a question, rather than a statement. You mentioned that vision should be stable. What does that mean? Are we talking six months, one year, two years?

Answer: Preferably, congenital in nature, present since birth. Because as the person grows and matures, he or she becomes accustomed to their low vision condition and their perception of the world through those functional parameters. The person's success in many instances is conditional or resultant to past parental upbringing, where for instance parents may or may not of permitted their son or daughter to participate in sports, bicycling, or pedestrian travel independently away from their home surroundings.

What we found in the WV Low Vision Driving Study, 1985-1995, is that though 107 individuals were identified as meeting the arbitrarily set visual protocol for inclusion in our study, not all wanted to participate. In fact, as a result of further screening procedures and participation in intensive driver education training ( 2 hours of classroom, 2 hours of passenger-in-car, 2 hours of behind-the wheel training, and normally at least an additional 2 hours of self-study per day, for 6-8 weeks) only about 30 per cent of our population sample were able satisfy the requirements for completion of our program and considered driver ready for application for WV driver licensure.

Statement by Dr. Mogk: That's what I thought you meant. There is a lot of confusion about that term in the senior population and the people who care for them, because often people are described as having stable macular degeneration.

Response: One of the things I think we should all remember is that persons who develop age-related dry macular degeneration oftentimes had normal visual acuity and fields of vision in their growing years, along with a 20/20 brain. As they age and develop macular degeneration (along with the reduction in visual acuity functioning, say 20/200 in their better functioning eye), they are still trying to interpret the world around them with a 20/20 brain. And that is where as a driver evaluator or driver educator you will notice or observe such individuals illustrating orientation related difficulties, because of their desire to still remain orientated to their surroundings with their former 20/20 brain.

Concern (from Dr. Mogk): That I certainly understand. The further concern is, as soon as they are fitted and trained, their scotoma changes.

Response: Remember, the BiOptic training exercise that I shared with you is only a small fraction of the extensive passenger-in-car training which respective candidates participate in as part of their formalized program of low vision driver education training and assessment. The enclose newsletter article will give a better awareness of the various stages of screening, training and assessment included in our respective program of instruction. In fact, the WV Code allows us to screen, train and assess potential drivers without a valid WV instructional permit, as long as such instruction is provided by a driver educator licensed by the State and conducted in a dual brake controlled vehicle. The latter allows us to adequately determine which candidates are v. are not driver ready for continuance with driver education training and subsequently application for driver licensure. And sometimes it takes 3-4 weeks to determine the latter.

Concern (Dr. Barry Skarf, M.D.): I'm a neuro-ophthalmologist. I wanted to point out also regarding the question of Dr. Mogk. The younger the person - it does not have to be in my experience - a congenital defect; though people with congenital defects amaze me at the ability they have just learned because their brain has worked with what they have been born with.

But even young people, as teenagers, or I have a young fellow who was 10 years old when he lost part of his vision - or even in their thirties or forties - they're motivated, and they are willing to make an effort, and they got a stable condition. For instance, a young person who lost bilateral vision due to optic atrophy, let's say hereditary optic atrophy, it's a condition where you you lose central vision, but once you lose it, it's stable, and those people are often 20/200. Those people, if they're motivated, can learn to function better, but I think that the older a person gets, motivation isn't related to age , and learning isn't related to age, but there is a co-relation. It becomes a problem. Unfortunately, that age population is the one that has the big numbers.

Response: I agree with you Dr. Skarf. I would also like to point out that it has been our experience in West Virginia, that environmental awareness training or re-training with prospective low vision drivers, regardless of age or onset of their respective visual impairment, is facilitated if we break down the various groups of critical objects or conditions into subgroups and have students learn or re-learn to detect and identify such objects or conditions one subgroup at a time.  For example, with the student positioned as a passenger in the front right seat of the driver education vehicle, have them practice detecting and identifying verbally the larger and more noticeable roadway characteristics such as a dip in the road, curve in the road, hill ahead, fixed hazards in or along side of the roadway which restrict or interfere with other road users' line of sight to them and their line of sight to other road users.

Then practice detecting other road users, whether they be on two feet or four feet, two wheels or several wheels.

Then, integrating the proper and appropriate use of their prescription BiOptic lens system; having the student practice detecting detail or signage off of distantly positioned road signs, color off of traffic lights, or other forms of activity or other gross movement in their magnified field(s) of view which may need to be responded to in terms of speed and or lane position adjustment of their vehicle when driving.

In other words starting with the big picture of their driving environment, and then locating more specific detail within that ever changing dynamic setting.

Concern (by Dr. Hessburg): I think that one of the things that distinguishes the West Virginia program from others that we've seen is that your program is more intensive. I know that in some States, and I have anecdotal evidence in our own State, that people use their dispensed BiOptic lens system to take the test and never drive with them on. They use the BiOptic lens system to pass the test (20/40 letters or numbers of an acuity chart) because of the magnification of the latter device But the latter device is not being used during driving. Whether they are not being trained properly, or whether our State does not require them to be trained, I do not know. But when I see them in my office, and I ask them, " how much of the time do you drive using the device?" They say " well, I always have it in the car with me ".

Response: It has been our experience that if lack of use of the device does occur, it is more likely to take place with individuals presenting more mild levels of visual acuity loss (say in the range of 20/50-20/70); and less likely to be abused or non used by individuals with more moderate levels of visual acuity loss (say in the 20/80 - 20/120 range or 20/140 -20/200 range).

Like any device, if someone is taught how to properly utilize the device, especially as it presents itself here under dynamic conditions (and the benefits of its usage is made known or experienced by the user, under real world driving conditions, the likelihood of use is enhanced several-fold.

On a separate note and related to your statement Dr. Hessburg, the visual screening in West Virginia, is usually waived and replaced by results of a complete eye examination , provided by a licensed ophthalmologist or optometrist of a student's choice, on a form called a Driver License Advisory Board Vision Report Form (DLAB-2 Form), which is then sent to our DMV headquarters in Charleston, WV, reviewed by our State's DMV Medical Advisory Board; and then recommendation is made to the DMV Commissioner as to whether or not to issue or deny an instructional permit for driving.

Concern (by Kathleen Miller, OTR/L): I am an Occupational Therapist, employed by Edwin Shaw Hospital, Akron, OH. I do training with low vision clients. I initially started as an occupational therapist doing driver evaluations for people with disabilities, such as strokes, head injuries, amputations, various problems. I was approached by an optometrist in Ohio to do the training aspect of it in the Akron area. The Columbus area also has a program, and they have been established for approximately nine to ten years.

So they have a pretty established program, but typically, the clients need to go to an established clinician that deals with these programs, and they need to be prescribed telescopes through these experienced professionals.

Then they need to have a mobility specialist who takes them out to make sure that they know how to use them as intended.

Then in turn they come to professionals like myself and we do the on-road training, including the correct integration and utilization of their prescription BiOptic lens system during the driving task.. If they are able to complete all of the above types of training and requirements, then and only then are they permitted to apply for driver licensure in the State of Ohio. The State of Ohio has specifically trained officers or driver license examiners that test prospective low vision applicants for driver licensure. Perhaps the lack of formalized programs of low vision driver education training and assessment in other respective States, that also license BiOptic driver applicants, is one main reason why some such drivers under-utilize or never realize the true benefits derived from their use under dynamic real world driving conditions.

Response: Thank you for bringing the latter to the attention of attendees of this colloquium. I am very familiar with the formalized programs of low vision driver education training and testing in States such as Ohio, Indiana, Virginia, Maryland and most recently Kentucky where fellow staff and I from the WV Rehabilitation Center have been directly involved in staff training issues (including DMV or DPS driver examiners and supervisory personnel), legislative efforts, and program development in years past.

If you have another concern or question regarding the use of a BiOptic during the driving task, please post it here.

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Below is the collection of slides from Chuck Huss' presentation


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1 - Frontal view of Designs for Vision, Inc. (DVI) 2.2X Galilean BIO II binocular mock-up BiOptic telescopic lens system in standard black Yeoman frame (note the physical location of telescopic units - above the normal viewing area through the carrier or support lenses)

2 - Lateral view of student viewing through the carrier lens of his DVI 2.2X Galilean Eagle Eye BIO II BiOptic telescopic lens system (note the ten degree drilling angle through the carrier lens for proper mounting of the telescopic unit for efficient vertical spotting purposes)

3 - Posterior view of DVI 2.2X Galilean Eagle Eye BIO II BiOptic telescopic lens system (complete with spring-loaded hinges and adjustable nose pads for snug fit and clinical adjustment if needed)

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4 - Rural driving scene in WV illustrating a straight stretch of roadway where proper use of a BiOptic telescopic lens system as a vertical spotting device would enable a driver to detect and react to the printed information or symbol messages presented on typical road signs

5 - Medium business driving scene in WV where use of the BiOptic telescopic lens system as a vertical spotting device would enable the user to spot the necessary detail or color off of ancillary pavement markings (turn arrows) and traffic lights respectfully far enough in advance for a driver to adjust speed and/or lane position to meet the demands of the intended driving task


6 - Small business driving scene in WV where ample eye lead time (intended location of your vehicle down the roadway in the next so many seconds of driving) and BiOptic usage if necessary, would increase a driver's margin of safety; enabling the driver to begin deciding and undertaking the necessary adjustments in speed and/or lane position to avert encounters with other critical objects or forms within or along side his/her path of travel v. reliance on detail gathered off of approaching road signs

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7 - Lateral view of student viewing through the carrier lens of his DVI 2.2X Eagle Eye BIO II BiOptic telescopic lens system (note, student's view through carrier lens is directly below and within close proximity to the telescopic housing; an advantage of using frames with adjustable nose pads - to optimize viewing area and minimize fixation time from carrier lens to telescopic lens and back)

8 - Lateral view of student viewing through the telescopic lens of his DVI 2.2X Galilean Eagle Eye BIO II BiOptic telescopic lens system (time spent viewing through telescope is .5 of a second or less per fixation)

9 - Metropolitan driving scene in WV emphasizing the need for drivers to: stay out of each others' blind spots, not tailgate and keep their eyes moving (DO NOT STARE) to obtain the big picture and react to the demands of the dynamic driving scene

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10 - Student with head mounted transceiver and BiOptic telescopic lens system in place, looking down two-lane roadway, responding to instructor's questions relative to instructor's movements and facial positions (results in students' self-realization of what they can detect and decipher at varying distances and lighting conditions while instructor is stationery or moving)

11 - Student and instructor discussing the actual v. apparent linear distance relationships from prepared distance measurement sheets when changing view from carrier to telescopic lens (for ex. when positioned at 20 yards, the student will notice an apparent reduction of half the true linear distance when changing fixation from carrier lens to telescopic lens viewing while using a 2.0X BiOptic telescopic lens system)

12 - Posterior view of student looking down roadway and mimicking the movements of the instructor from varying ten yard incremental distances through carrier v. telescopic lens ( Note, telescopic viewing not only enhances user's distant detail and color perception but also movement of objects or forms)

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13 - Frontal view of person viewing through the telescopic unit of a 3.0X DVI binocular Galilean BIO I BiOptic telescopic lens system (trained BiOptic users learn to adjust readily to the brief angular scotoma or absence of visible viewing area created by binocular mounted telescopic lens systems or monocular systems if the person functions monocularly, without affecting their awareness of their peripheral surroundings)

14 - Four (4) DVI Galilean BiOptic telescopic lens systems of the same dioptric strength, yet different in size, style, field of view, use , weight, etc. (Oftentimes, the larger in size units are perceived inadvertently as being stronger in terms of magnification )

15 - Lateral view of person looking through Edward's Optical Bi-level Telemicroscopic Apparatus (BITA) Vision Enhancer (Note this unit's small size, apparent lighter weight, improved cosmesis and potential for increased awareness of one's para-central and peripheral fields of view while viewing through the telescopic portion of the device)

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16 - Posterior lateral view of student participating in an indoor vertical spotting training exercise while using his BiOptic lens system ( note, because of vertex distance in BiOptic telescopic lens systems - the linear distance between the cornea of one's eye(s) and a carrier lens or ocular lens of a telescopic lens unit, a person is able to follow or track movement in their periphery quite effectively as illustrated)

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roadway construction site, illustrating where drivers, even when traveling
in familiar areas or on familiar roadways, have no control over what happens outside of their vehicle relative to other road users, roadway conditions, weather, etc. Thus ample eye-lead time and proper BiOptic usage could increase the margin of safety for the low vision driver considerably

18 - Lateral view of student viewing through the telescopic lens of his DVI 2.2X Galilean Eagle Eye BIO II BiOptic telescopic lens system (Note, one DOES NOT continually view through the telescopic portion of their BiOptic lens system, but rather intermittently for .5 second intervals on primarily vertical spotting related tasks as needed)

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19 - Medium business driving scene in WV presenting traffic lights suspended from the far side of a multi-lane cross road and multi-directional route signs on near right corner of intersection (serves as an excellent reason why lower acuity drivers should use BiOptic telescopic lens systems v. approach magnification methods ( the latter entailing driving slower and getting closer to an object or form of concern before detecting and deciding what action to pursue) to increase one's margin of safety. If the appropriate sign or traffic light is detected soon enough, the driver is able to move into the appropriate lane while legal to do so or prevent driving beyond painted stop lines, crosswalks or into the intersection itself.

20 - Student with BITA lens system  posing proudly with newly acquired driver's license ( ***** the most common concern or limitation expressed by physically challenged individuals, especially visually challenged individuals in attempting to find or keep a job or live independently in a rural State, is TRANSPORTATION)

21 - Clinician performing part of his low vision examination (obtaining distance visual acuity readings of patient one eye at a time)

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22 - Student participating in automated perimetry testing conducted by clinician's assistant (objectively assessing one's central and peripheral fields of view using a Humphrey's Field Analyzer)

23 - Clinician evaluating and fitting a monocular mounted DVI Galilean BIO I 4.0 X BiOptic telescopic lens system to patient as part of the low vision examination (using a DVI manufactured slotted trial frame, accessory trial rings and spacers as needed ) in preparation for participation in formalized low vision driver education training and assessment.

24 - Posterior view of DVI Yeoman Frame typically used for evaluating and fitting BiOptic telescopic lens systems (including slotted carrier lenses, trial lens retainer rings, adjustable nose pads and spring loaded hinges)

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25 - DVI mock-up trial frame ( including slotted carrier lenses, locking rings, spacers, Galilean v. Expanded Field Prism telescope

26 - Birdseye/overhead view of DVI 2.2X Galilean BIO II BiOptic telescopic lens system in black Yeoman frame with velcro strap (the latter decreases the probability of system breakage or becoming a projectile in the event of an impact collision with other road users or roadway characteristics.

27 - Birdseye/overhead view of DVI 3.0X Galilean BIO I BiOptic telescopic lens system with drilled to fit slip-in sunshade in place

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28 - Lateral view of person viewing through the telescopic unit of a DVI 4.0X Expanded Field Prism BiOptic telescopic lens system (though weight, size, and cost is greater, the clarity and field of view through this type of telescopic unit is better or larger than most DVI Galilean BiOptic telescopic lens systems

29 - Frontal view of one of Edward's Optical BITA binocular mock-up lens systems (note how the tinted superior portion of the carrier lenses camouflages the presence and location of the built-in miniature binocular BiOptic lens system … which has gained particular acceptance by younger age telescopic lens users)

30 - Frontal view of young female with a BITA lens system in place inconspicuously in typical classroom setting

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31 - Posterior lateral view of an Ocutech, Inc. Vision Enhancing System (VES), focusable from distance to  twelve inches if needed

32 - Frontal view of female with an Ocutech, Inc. Vision Enhancing System (VES) in place

33 - Frontal comparison view of a DVI 3.0X Expanded Field Prism BiOptic telescopic lens system (to the left) v. an Ocutech, Inc. 3.0X Vision Enhancing System (VES) - MINI BiOptic telescopic lens system (to the right)

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34 - Frontal view of female wearing an Optical Designs, Inc. Behind- The - Lens Telescope (Note, the designer of this system indicates that the inferior or inferior temporal placement of this telescopic device requires users to make a 36 degree lateral rotation of the eye, to look through the telescope to see what is directly in front of them; no head movement is required as is the case with most other BiOptic telescopic lens systems)

35 - Posterior lateral view of a M-Tech Optics Corporation's 4.0X M-Lens System (Note the unique needle- like slide lever which allows the user to efficiently change focus from distance to near ranges without physically touching the housing of the miniature telescope)

36 - Box containing Doron Corporation's complete set of filmstrip-cassettes covering all phases of hazard perception and independent decision making (the latter audio-visual materials is also available for purchase in laser disc or 16 mm film format)

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37 - Example of eye-lead time (the location of your vehicle in the next so many seconds of driving time. As vehicle speed increases, so must your eye lead time in order to drive safely and maintain an adequate margin of safety from other critical objects or conditions in your driving space ( Source: American Automobile Association filmstrip-cassette library)

38 - Driving scene of basic skill small business route in WV illustrating the need to scan early and repeatedly as you approach an intersection (note the location of the car in the intersection and the color of the traffic light facing perpendicular away from the intersection)

39 - Driving scene of basic skill interstate route in WV illustrating the recommended 3 - 4 second in length following distance from vehicles ahead of your vehicle, and behind when possible (Note, greater following distances are recommended when following trucks or other larger in-size vehicles, Source: Doron Corporation)


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40 - Frontal view of student indicating to instructor by extending his right hand and arm out the driver's
side window when instructor's presence enters the left rear side blind spot area of the inside rearview mirror of the stationary driver education vehicle

41 - Driving scene of mid skill medium business route in WV illustrating the need for ample lateral eye scanning and eye lead time to detect the offset stop signs suspended by wires above and amidst the bush at the near right corner of this wide intersection

42 - Driving scene of basic skill residential route in WV illustrating that as one approaches an unlighted yet controlled plus-shaped intersection, the recommended sequence of visual scanning by a driver to determine who must stop and yield is to first view the near right corner, then the far left corner, then the near left corner, and lastly the far right corner respectfully before one proceeds into the intersection

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43 - Driving scene of advanced skill metropolitan route in WV illustrating inadequate following distance from the larger in size vehicle ahead (Note, following too close to other road users, as in this case, takes away one's safe escape to the right or left in potential crash avoidance situations …. where the presence of other road users or traffic control devices ahead goes undetected)

44 - Driving scene of advanced skill metropolitan route in WV illustrating adequate following distance to the large in size vehicle ahead (Note, the ability to detect the presence of other road users and traffic control devices ahead and to either side of the vehicle ahead; and if following distance is even greater, the ability of the truck driver to detect your presence through his side view mirrors respectively)

45 - Campus driving scene in WV illustrating how all students who participated in the training phase of the WV Low Vision Driving Study, 1985-1995 were required to have their prescription BiOptic telescopic lens system in place starting day 1 of the behind-the wheel phase of training, though integration of the actual use of the device into the driving task in most cases was not illustrated until the beginning of the second week of training (rationale behind this was to acquaint project participants with the need to learn to view below the telescopic portion of the device for the greater majority of the driving time and driving experiences; and to only use the telescopic portion of the device for vertical spotting purposes when distant detail , color or movement awareness was necessary)

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46 - Driving scene of basic skill small business route in WV illustrating the need for drivers to be able to use closure principles to blend incomplete visual scenes within their ever-changing driving environment in order to make appropriate driving decisions to avoid contact with other road users who share the same roadways (in this case filling in the portions of the approaching stop sign partially hidden by the tree to recognize that the driver must come to a stop before proceeding straight , left or right at the approaching intersection)

47 - Driving scene of advanced skill rural route in WV illustrating the need for all drivers, especially low vision drivers to be able to adjust to expected and unexpected lighting changes when driving task involves driving in various compass directions, times of the day, weather conditions, environmental conditions , different seasons of the year, etc.

48 - Driving scene of mid skill small business route in WV illustrating the need for all drivers, especially low vision drivers to be able to detect changes in traffic flow patterns well in advance to avoid contact with other road users ( Note, clues provided by overhead and distantly positioned regulatory signs, longitudinal and transverse pavement markings, and the position and direction of travel of other road users assist the driver in this situation as to what is v. is not permissible by law

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49 - Driving scene of advanced skill rural route in WV illustrating the need for drivers, especially neophyte low vision drivers to interpret correctly the message conveyed by the warning sign (left turn ahead) not immediately but further down the roadway as will become evident

50 - Driving scene of advanced skill rural route in WV illustrating the need for all drivers, especially low vision drivers to be able to adjust quickly to expected and sudden/abrupt changes in natural or environmental lighting (Note, in order to negotiate this curved 30 - 35 yard in length stretch of roadway through this old railroad tunnel, one needs to come to a stop, turn on their head lights, roll down their window, listen for any approaching traffic sounds coming from the one-lane roadway through the tunnel; and if all is quiet, to proceed cautiously at a low rate of speed through the tunnel which has a lateral clearance of approximately 2-3 feet to either side of your vehicle)



To Find out more...

Where to get information on Driver Training:


The Association of Driver Educators for the Disabled (ADED) provides information on driver rehabilitation programs that include low vision driver training with spectacle mounted telescopes. For more information contact ADED in the USA by telephone: 608 884-8833.  Email , or access their website: http://www.driver-ed.org


Also contact the Academy for Certification of Vision Rehabilitation and Education Professionals, (ACVREP)  Call 520 887-6816 or visit their website www.acvrep.org  




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Those interested in more information can also write or call: 

Charles P. Huss, C.O.M.S. Coordinator, Low Vision Driver Services

West Virginia Rehabilitation Center P.O. Box 1004 Barron Drive Institute, WV 25112 TEL: 304-766-4803 FAX: 304-766-4816  Charles P. Huss is an Academy Certified Orientation and Mobility Specialist with 25 years of teaching experience with visually impaired individuals (K-Geriatrics). 



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Disclaimer statement: BiOptic Driving Network does not sell, endorse, or offer opinions on products, manufacturers, or professionals whose services/products may be secured following posting on this website.  Products and individuals pictures on this site have been specifically authorized by the relevant manufacturer or individual.  We are a registered not for profit organization, and provide information to help make informed choices.  We do not give individuals optometric or ophthalmologic advice, but may refer one to an eminent expert.  A BiOptic Telescopic System does not itself make someone a safe driver; specialized training is prerequisite.