Driving with Multifocal Contact Lenses - Dangerous?
The Dangers of Driving with Multifocal Contact Lenses
One of the big downsides to aging is that vision tends to deteriorate. This can result in needing glasses or contacts to see or drive properly. In some cases you will need multiple prescriptions to see near and far distances. For years the only solution to this was wearing bi-focals. Recently new multi-focal contact lenses have entered the market. These are great alternatives to bi-focals and can make wearing contacts a possibility for those that have trouble seeing up close. While these multi-focal contact lenses can eliminate the need for bi-focals, research suggests that they may be unsafe when driving, especially at night.
Why Would You Need Multi-Focal Lenses?
Bi-focals are typically only worn by older adults. As the body ages it has more difficulty focusing on objects that are up close. This condition is known as presbyopia. Bi-focals can remedy this problem while still correcting other vision problems as well. Multi-focal contact lenses are worn just like other contact lenses. However, they are able to offer the same vision flexibility as a pair of bi-focal or tri-focal glasses. Multi-focal lenses are available in a wide variety of contact styles including soft, rigid gas permeable and hybrid lenses.
Contacts and Driving
Traditionally contacts have been the best choice for drivers that are driving at night. Glasses tend to produce a glare, while contacts do not. While traditional contacts might be the safest when driving at night, the same is not true of multi-focal lenses.
Driving at night and driving during the day are very different. It can be more difficult to see during the night and sharpness and color are greatly obscured. This is primarily because the eye uses different parts for night and day vision. Your retina contains 2 different types of cells, rods and cones. The cones require a lot light to function but provide sharper images and color. Rods are highly sensitive to light and can pick up light even when there is very little. When driving at night, the driver must rely almost entirely on their rods which can make it more difficult to see.
A recent study published in Investigative Ophthalmology and Visual Science suggests that multi-focal lenses can be very dangerous when driving. The study found that drivers wearing multi-focal lenses at night drove quite a bit more slowly than those wearing glasses. The study also found that they were less likely to notice hazards in the roadway. Those wearing glasses were also able to see road signs at a greater distance than those with multi-focal contact lenses.
There were 11 participants in this study. The average age of participant was 57.3 years, but ages ranged from 45-64. The adults in the study were not regular users of contact lenses or glasses for near sightedness. In fact, study participants had only used reading glasses to correct nearsightedness in the past.
This study was conducted on a closed track, not actual roadways. Each participant was tested in 5 distinct areas which included being able to see road signs, identifying road hazards, staying in their lane and more.
This study should be cause for serious consideration if you are planning on driving long distances at night while wearing multi-focal lenses. However, this study is not comprehensive proof that driving with multi-focal lenses is a problem. There are several limitations to this study that will need to be addressed to really determine if multi-focal lenses impair driving at night.
One downside to this study is that there were only 11 participants. It can be difficult to properly determine if the lenses were impacting driving on such a small study group. Driving ability skill varies greatly, so a large group would be needed for comprehensive results. Also since the drivers were not regular users of multi-focal lenses, it is possible that these effects could lessen with time. Multi-focal lenses do take some getting used to. They may have less of an impact on night driving for those that have worn them for a while and understand how they work.
Future studies using larger sample groups and long term wearers of multi-focal contacts are needed. These studies will provide valuable information into these lenses and will help determine if they are a safe choice for driving at night. In the meantime, be very careful if you decide to wear multi-focal contacts at night. If you have a hard time seeing, it might be worth switching to glasses for nighttime driving. It is always best to be safe rather than sorry.
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