With Winter Here, Take Extra Care On The Road
With the winter season upon us, the days are shorter and the roads more dangerous. According to the National Safety Council, the risk of a fatal crash is three times greater at night.
While snow and ice demand careful driving, it’s equally important to consider night vision problems that can be more pronounced during winter.
This is especially true for older drivers. According to the American Optometric Association, a 50-year-old driver may need twice as much light to see as well as a 30-year-old. At age 60, driving can become even more difficult.
Depth perception, color recognition and peripheral vision can all be compromised at night. Even with high-beam lights, visibility is limited to 500 feet (250 feet for normal headlights,) giving drivers less time to react. Headlight glare from oncoming vehicles can also temporarily blind drivers. Individuals with cataracts have a particularly difficult time with glare from headlights, making night driving very difficult to impossible.
The most important factors for safe driving are visual acuity and field of vision. Visual acuity is the sharpness of your vision, measured by the ability to discern letters or numbers at a given distance according to a fixed standard. Visual field is how wide of an area your eye can see when focusing on a central point. Additionally, color vision helps to identify traffic signals and brake lights. Contrast sensitivity aids in identifying pedestrians, lights and road signs.
There are a myriad of eye conditions and diseases that affect night driving, including the need for glasses, cataracts, glaucoma, diabetic retinopathy and macular degeneration.
In states where periodic mandatory vision screening is required of senior drivers, most cases of potential loss of license due to poor vision are due to the need for glasses or a change in existing glasses. New Jersey, unfortunately, is not one of those states.
Nonetheless, it is important to have regular eye exams with your eyecare provider to detect and treat problems that impact nighttime vision.
February 4, 2019
Does Marijuana Really Help Treat Glaucoma?
Medical marijuana is a popular treatment for a variety of maladies. Glaucoma, a disease of the optic nerve which can lead to vision loss and blindness, is often understood to be one of them. But while medical marijuana maintains several therapeutic uses, it is ineffective in the management of glaucoma.
Glaucoma is treated with medicated eyedrops to lower the pressure within the eye. Marijuana can also lower this pressure. The problem is that marijuana also lowers blood pressure. This can have negative effects on the optic nerve, the structure damaged by the high pressure in glaucoma.
Another problem with marijuana is the pressure lowering effect lasts only three to four hours. This short duration means that a user needs to consume the drug about six to eight times a day to effectively keep eye pressure low.
Unfortunately, the same ingredient in marijuana that lowers eye pressure also produces a high. For most people, controlling their glaucoma with a mind and mood altering drug that needs to be used every three to four hours is not a very good idea.
Marijuana impairs the ability to perform complex tasks such as driving, operating heavy machinery and functioning at maximum mental capacity. Medical marijuana, if smoked, also contains hundreds of compounds that damage the lungs. Chronic, frequent use can also damage the brain.
These concerns and limitations lead the ophthalmology community to conclude that recommending marijuana to treat glaucoma is not in our patients’ best interest.
A comprehensive eye exam is the best way to diagnose and treat glaucoma. Depending on the severity of the condition, your ophthalmologist may recommend treatment ranging from prescription eye drops to laser treatments to surgery.
January 4, 2019
Are Eye Whitening Drops Safe?
Judging from a Google search of ‘Visine and other Eye Whiteners’ (yielding 14 pages of hits,) a lot of people have red and inflamed eyes. We Americans spend about $600 million annually on Visine, Clear Eyes and other similar eye whiteners. Are they safe and effective? The answers are complicated.
There is great interest in eye whitening for a variety of cosmetic and social reasons, (e.g., eye redness from allergies, contact lens wear, environmental irritants, excessive alcohol use, etc.) All of these products do provide temporary eye whitening. So why the concern?
Ophthalmologists are concerned about the masking of more serious eye diseases that cause redness. There are many, including infections, contact lens-related problems, inflammatory diseases and glaucoma. As a rule of thumb, any eye redness that causes pain, reduces eyesight or doesn’t resolve promptly needs medical attention and should not be self-medicated with eye whiteners.
‘Rebound’ redness is another major concern of eye whiteners. Prolonged use can cause a form of addiction whereby stopping the drops causes rebound redness worse than when the redness first started.
Lumify is a new player on the market having received FDA approval late last year. Lumify’s appeal is that it does not cause rebound redness. It actually is a spin-off of a popular glaucoma medication, which has eye whitening as a ‘side effect’. Since Lumify is a very low-dose formulation of a drug that’s been around for years, it’s unlikely to have any long-term problems. It does contain a preservative that can cause significant irritation, especially if used frequently.
The concern about masking of more serious eye disease, of course, remains the same. Ads for Lumify state the drops can be used four times a day. “However, anyone who thinks they need drops that often should first have their eyes checked by an ophthalmologist to find out what's causing the redness,” says Laurie Barber, MD, a spokesperson for the American Academy of Ophthalmology.
November 27, 2018