Driving with a Bioptic Telescope:
Concepts and Techniques

Content derived and edited from “Essentials of Low Vision Practice”
Butterworth-Heinmann Publishers 1999

By:
Richard L. Brilliant, OD, FAAO,
Associate Professor of Optometry
Pennsylvania College of Optometry
Senior Low Vision Practitioner
William Feinbloom Vision Rehabilitation Center
The Eye Institute, Philadelphia

Used by permission of the author

Introduction:
Depending upon state licensing regulations, individuals with a visual impairment, within a specific range of visual acuities, may be eligible to receive a driver’s license (usually with some level of restrictions) if they can fulfill and comply with their state’s specific regulations.

Bioptic telescopes are eyeglasses that contain the individual’s regular distance vision prescription (if any) and include miniature telescope(s) mounted toward the top of the eyeglass above the individual’s line of sight. Individuals who drive using a bioptic telescope look through the regular eyeglass lenses (carrier lenses) most of the time and only site through the telescopebriefly similar to the way one uses the side and rearview mirrors. The telescopic device enables the driver to see further forward to enable them to better maintain lane position, avoid obstacles, anticipate traffic, and see pedestrians, bicyclists, signs and signals.

Generally, the driver will only look through the telescope 2-3% of the time. As a result, the driver must be a competent driver without the use of the bioptic. The bioptic will not enable an incompetent driver to become competent. However, a competent visually impaired driver can become a safe driver with the use of a bioptic telescope.

There are two aspects to safe driving—operating the vehicle appropriately (on-road safety) and finding one’s way (wayfinding).

To support safe driving while using a bioptic telescope, two techniques need to be mastered—scanning (localizing) and spotting(identifying).

Scanning
Scanning may be the most challenging technique for the visually impaired driver to master. Scanning allows the bioptic driver to inspect traffic conditions at a further distance (approximately 100 yards or more) that could not be seen without the bioptic. Scanning allows the driver to become aware of situations or hazards while driving which they will want to identify by spotting with the bioptic.

Spotting
To spot an object, the driver initially locates the object with their regular vision by scanning (through the carrier lenses), and then transfers their visual attention to look through the telescope to identify the object of regard. Once the object is identified the driver immediately returns to viewing through the carrier lenses. The spotting process should be brief, fast and reflexive.

Visibility while driving is impacted by three factors— object vision, visual clutter, and speed.

Object vision
When driving, objects do not always have to be identified in order to drive safely. One does not have to know what type of object is lying in the road, or what kind of ball is rolling out between cars, just that it is there and needs to be avoided.

Visual clutter
There are many objects on and along the road. Many are of no importance and do not influence safe driving. The challenge, of course, is to know which are important. Differentiating between stationary and moving vehicles, trees, utility poles, signs, signals, road workers and pedestrians will help to make the visually impaired driver as safe a driver as possible.

Speed
The faster one travels the faster one must scan (locate) and spot (identify) relevant information from among the visual clutter on the road, and hence the greater the challenge to do it effectively. While looking through a telescope, motion will appear exaggerated further increasing the visual demands. Reducing driving speed will provide extra time to effectively view the driving environment. However, driving too slow may cause the visually impaired driver to become a hazard to others on the road.

It is obvious, that with these factors in mind, it is far easier and safer to drive in familiar, low speed areas.

Driver Training Exercises

  1. Target practice outside the car 
    1. From a stationary position learn to spot a stationary target
      1. The driver should locate the target through the carrier lens, drop his/her head down to sight through the telescope to view the target (translation) and once identified immediately return to viewing through the carrier lens.
      2. Work for accuracy first, speed second
      3. The goal is to accomplish this activity in less than one second
    2. From a stationary position, spot and track a moving target
      1. Targets can move side to side, in and out, or both
      2. As moving targets get closer they will appear to move faster and more head movement will be required to track the them
  2. In car training as a passenger
    1. From a moving car, the bioptic user should spot stationary targets
    2. From a moving car, the bioptic user should track moving targets
  3. In car training as a driver
    1. The first driving experience should be on a four-lane, controlled access highway (having no cross traffic or stoplights) because this is the easiest way to start driving with a minimum of distractions
      1. The driver should know in advance where to exit
      2. The driver should learn to identify, but not necessarily read, every sign that is passed
      3. The driver should learn to make scanning movements with the telescope to view traffic conditions further ahead than can be seen with their normal vision. This scanning should be performed 3 to 6 times per minute.
      4. The driver should use the side and rearview mirrors to keep track of surrounding traffic. When spotting objects through the mirror that area at a greater distance, the bioptic can be used.
    2. Driving on residential streets (25-35mph zone)
      1. This type of street may have a lot of visual clutter, however driving speed is slow enough to allow ample time to spot and identify all relevant targets
      2. The driver must use frequent scanning movements, sweeping fully to both sides of the street.
      3. The driver must be alert for pedestrians and children as this is the environment where they are most likely to be encountered.
      4. The particular street and time of day should be considered to avoid encountering school buses and school children.
    3. Driving on major traffic arteries (45-65mph zone)
      1. The speed is faster but with usually with less visual clutter
      2. The driver should at first use a familiar road, knowing where to exit and avoiding rush hour and poor weather conditions.
      3. The driver should not allow their speed to drop more than 10mph below the posted speed limits (it is safest to drive at a speed consistent with other appropriate traffic).
    4. Driving in downtown rush-hour traffic
      1. There may be a psychological barrier to be addressed that heavy traffic makes driving more difficult.
      2. The route should be familiar and pre-planned.
      3. The driver should at first stay in the right lane.
      4. If the driver is first in line at a light, he/she should aim the telescope at the proper traffic signal and wait for the light to change to green. They should then sight through the carrier lenses to confirm that no pedestrians or traffic are in or entering the intersection before continuing on.
      5. The driver should never move so close to the vehicle in front that the rear tires of that vehicle are not visible (tailgating).
    5. Driving on a commercial street or business district
      1. These streets are generally the most difficult to manage as there is a lot of visual clutter and many targets to spot and identify.
      2. The driver should initially choose an off-peak time of day to avoid heavy traffic.
    6. Driving on a combination of streets and highways
      1. Until now, only one type of driving pattern or highway was encountered at a time. As a result a mindset and expectations will be developedfor each type of driving environment. The transition to encountering a combination of driving patterns will require a mental shift to different levels of scanning and spotting behavior for each area encountered.
    7. Driving the four-lane highway
      1. This highway may have cross traffic and traffic lights.
      2. Scanning is one of the most important techniques used on this type of roadway.
    8. Driving the two-lane highway
      1. This highway generally has narrow shoulders and follows the contour of the land.
      2. When overtaking and passing another vehicle, the driver should judge the distance of the vehicle in front using the carrier lens, and then use the telescope to spot ahead into the oncoming lane to determine that it is clear to pass.
      3. When passing, the driver should continue to view through the carrier lenses, alternating frequently into the telescope to continue to check for oncoming traffic.
    9. Driving the freeway
      1. This roadway usually has very little visual clutter, however there are lane positioning and exit signs that must be identified.
      2. This type of driving also encounters aggressive drivers who might tailgate, weave in and out of lanes. It is best to drive consistently and defensively by staying in one lane and letting these drivers pass.