Factors Affecting Myopia in Children
With the advent of computers, smartphones, Facebook and other technological wizardry, outdoor fun and games often take second place in the minds of our children. In some cultures, academic success places intense pressure on kids to read and study.
A report last year from the Organization for Economic Co-operation and Development showed that the average 15-year-old in Shanghai now spends 14 hours per week on homework, compared with five hours in the United Kingdom and six hours in the United States.
There is a worldwide epidemic of childhood nearsightedness (myopia). In Asia, upwards of 90% of young adults need glasses for myopia. In the 1950s, the incidence was 30%. In the US and UK, myopia rates have doubled in the last 50 years.
For most people, needing glasses or contact lenses is a nuisance. However, a small percentage of children will develop extreme myopia, which can lead to serious eye problems as adults.
While other factors including genetics come into play, the culprit appears to be lack of sunlight exposure. Previously, researchers noted that smarter kids were more likely to be myopic than kids who did less well in school. Thus, the conclusion that reading and studying were the cause of myopia. Wrong!
Newer research shows that the studious kids simply don’t spend enough time outdoors. Also, it doesn’t matter what kids are doing outdoors – playing, organized sports, reading or just hanging out. The more time outdoors, the lower the risk of myopia. This effect is greatest in those kids with two nearsighted parents, less with one parent and least but still possible with neither parent.
Excessive lengthening of the eye during childhood (not visible when looking at the child) is the cause of myopia. A just-released study from Taiwan showed that students who spent at least 200 minutes per week outside during school hours have significantly less worsening of nearsightedness and less excessive lengthening of the eyes.
Sunlight exposure, even in the shade, slows down this growth to a normal level. In a study of 6-year-old Chinese children, the addition of 40 minutes of outdoor activity a day reduced the incidence of myopia over the next three years.
March 1, 2019
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