Ridesharing can help older people be functionally independent in their homes, communities
Most of what you do behind the wheel is dependent on your eyesight. If you cannot see clearly, you are unable to judge distances or spot trouble.
Distance Judgment (Depth Perception)
You may see clearly but still may not be able to judge distances. Good distance judgment is essential in knowing how far you are from other vehicles.
Driving mistakes that indicate poor depth perception:
- Stopping too far from the stop line or intersection
- Stopping too close to vehicles in front
- Merging into gaps that are too small
- Following other vehicles at an unsafe following distance
- Hitting parked cars when parking
- Having "close calls" when entering traffic, passing, etc
Peripheral vision is being able to see what is happening to the sides of you, or "looking out of the corner of your eyes." You should be able to see hazards and react to the movement you see out of the corner of your eyes.
If you have subnormal peripheral vision, you can help compensate for it by looking side to side and by ensuring your side-view mirrors are correctly adjusted so that you can take in the whole scene.
Night vision is the ability to see clearly at night, especially signs, roads, and hazards. Older drivers often develop night vision problems.
Light blurs can "spread out" on the windshield and cause sheen that is difficult to see through.
This glare also makes it more difficult to judge distance.
Many people who may see clearly in the daytime have trouble seeing clearly at night. They get what is called "night blindness." Some people see poorly in dim light, and others may have problems with the glare of headlights. People who experience night blindness should avoid driving at night.
Color vision deficiency is sometimes called "color blindness" by mistake. The term describes several different problems people have with color vision.
Abnormal color vision may vary from not being able to tell certain colors apart to not being able to identify any color. This can be very hazardous because our traffic light system is based on colors; Red: Stop, Green: Go, Yellow: Yield. Without the ability to distinguish between different colors, you will be unable to tell when you should stop or go.
An estimated 8% of males and less than 1% of females have color vision problems.
There are several ways to test color vision. Simple tests involve colored figures (either shapes or numbers) placed against a busy, patterned background. A person with normal color vision can see the number 5 against the background in the image above. Those with color vision deficiencies cannot see the symbols.
Most color vision problems run in families and are inherited and present at birth. There are also some types caused by eye disease or injury. Unfortunately, there is no cure for hereditary color vision deficiency.
Many people with color vision deficiency develop their own "system" or learn to identify colors by other means. Some people learn to tell colors apart by brightness and location. Specially tinted eyeglasses may help some people with color vision deficiencies tell the difference between certain colors. These eyeglasses and other aids help but cannot restore normal color vision. If you suspect a color vision deficiency, consult your eye doctor as soon as possible.
Compensating for Subnormal Vision
If you have vision problems, get an eye examination from an optometrist. See if you can be fitted for eyeglasses or contact lenses. When driving, compensate for subnormal vision by looking side to side to take in the whole scene.
Tips to Compensate for Visual Limitations and Conditions
- Have your vision checked regularly
- Avoid driving at night whenever possible
- Avoid driving during adverse weather conditions
- Avoid driving in areas of low illumination
- Allow eyes to adjust to low illumination levels before starting out
- Reduce vehicle speed after sundown
- Keep vehicle windshield and headlights clean
- Keep interior car lights turned off
- Use high beams whenever possible and legal (though never in bad weather)
- Avoid looking directly at headlights; use quick glances to check approaching traffic.
- Look beyond lights or to the right of them.
- Keep panel lights at the highest illumination levels.
- Wear sunglasses only during daylight hours.
- Use day/night rearview mirrors to reduce glare
- Stay farther back from the car ahead
- When passing, allow for a greater distance ahead
- Use known distances, parked cars, city blocks, telephone poles to judge distances
- Move the eyes and head slightly to see movement to the sides
- Install special mirrors if movement is constricted
Additional Information About Vision Impairment
National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
Telephone: (301) 496-5248
Fax: (301) 402-1065
111 W. 59th St.
New York, NY 10022-1202
Telephone: (212) 821-9200
(800) 829-0500, TTY