Driving With Monocular Vision
Monday February 11, 2013
Nearly all children with retinoblastoma have complete or significant sight loss in at least one eye – most have an removed to save their life. “Will I/my child be able to drive?” is a common question among parents and teenage survivors. Our CEO, Abby White, who is registered blind and unable to drive due to eye cancer, explores the different considerations for drivers with reduced sight.
In many countries, driving with vision in only one eye is legal. The question of ability to drive usually relates to field of vision. Since removing an eye reduces the visual field by only about 2/5, enucleation alone is not a barrier to driving when the other eye has a very good visual field. However, there are some important things to bare in mind when driving with monocular vision.
Always test drive your chosen car thoroughly before buying, as visual comfort varies widely between makes and models.
For example, the rear window in many smaller cars gives a very restricted view. In combination with restricted visual field, these small windows create many dangerous blind spots that are not present with larger cars.
Practice three-point-turns, reversing, parallel parking, and changing lanes to determine whether the car gives you enough vision on all sides. Choose the car that feels safest to you when undertaking these manoeuvres.
A range of driving aids can improve vision for a monocular driver, making manoeuvres such as lane change and parking easier. Consider testing these out to determine whether they can make a difference to you.
- Larger wing mirrors on both sides
- Convex mirrors on both wing mirrors
- Rewipers and de-misters
- A wide rear vision mirror
- Reversing sensors
- Halogen headlights (maximise visibility at night)
Monocular vision often causes the brain to lose ability of assessing the distance to an object ahead. Children who lose an eye very early usually adjust very well so by the time they are old enough to drive, they have learned how to manage this loss and judge distances well. However, it is important that monocular drivers take special care to protect yourself and other drivers, especially in poor weather conditions.
- Always maintain a good distance between yourself and the car in front.
- Always observe the speed limit, and consider a speed alert system to help you stay within the limit.
- Do not drive when tired as fatigue changes depth perception even in healthy eyes.
Parallel and reverse parking can be challenging for fully sighted drivers. Monocular drivers must pay extra attention when executing these manoeuvres. Allow ample time and patience, and ask passengers to allow you to focus on the process. Use driving aids and don’t be afraid to ask others to help by guiding you in.
Monocular vision can be especially challenging at night due to contrast between the dark night and bright streetlights and headlamps of oncoming traffic. This can be especially true for bilateral retinoblastoma survivors who drive, as the seeing eye may be more sensitive to light due to treatment in childhood. Consider asking for a pair of night driving glasses – these have a special tinted lens to reduce glare. This coating can also be applied to prescription lenses.