According to the National Eye Institute, a part of the National Institutes of Health, 285 million people around the world are living with blindness or visual impairments. Moreover, the number of people in the US who are blind or visually impaired is expected to double to more than 8 million in the next three decades.
While most cases of low vision and blindness in the future will occur primarily as a natural consequence of aging, there are a number of factors scientists believe can contribute to reduced vision. The following are five factors that may affect eyesight and contribute to vision loss or even blindness.
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Sunlight
Ultraviolet (UV) rays from the sun can cause significant damage to eyes over time. Two forms of UV rays can affect vision: UV-A and UV-B. UV-A has been shown to cause damage to a central portion of the retina known as the macula, which serves as a platform for light focused by the cornea and the lens. UV-A rays can damage your central vision, while UV-B rays tend to damage the front part of the eye, particularly the frontal lens and the cornea.
The best way to protect the eyes from vision damage caused by UV rays is to always wear high-quality protective sunglasses that filter out this form of light. Overexposure to UV rays can be a problem for people who routinely work outdoors. These individuals are at an increased risk of eye diseases such as cataracts, macular degeneration and pterygium.
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Stress
Not only can long-term stress lead to cardiovascular disease and depression, but it can also affect your ability to see.
Arguably the most serious way that stress can induce vision loss is through a condition known as central serous retinopathy. Stress is believed to contribute to the condition, which occurs when fluid builds up within the eye, specifically behind the retina. The fluid buildup may cause the retina to detach, impairing a person’s vision. Typically, the condition occurs in only one eye, and the primary symptom is blurry vision.
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Smoking
Approximately 37 million people in the United States smoke, according to data from the Centers for Disease Control and Prevention. While they may be aware of the damage smoking can cause to the body, they may not realize the habit could eventually lead to severe vision loss or even total blindness.
A smoking habit is a risk factor for all of the serious major eye diseases, including glaucoma, age-related macular degeneration (AMD), cataracts and diabetic retinopathy. Smokers are between three and four times more likely to be diagnosed with AMD and three times as likely to develop cataracts as non-smokers. Smoking also contributes to elevated blood pressure levels, which are known to be a risk factor for glaucoma. Smoking may even increase the risk of developing diabetes. Moreover, heavy smokers are twice as likely to develop diabetes than non-smokers.
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Medications
While medications prescribed by a licensed medical professional can be useful in the treatment of a specific illness, it’s important for people taking medicine to be aware of the possible side effects and to monitor their vision to detect changes. Many medications, such as those prescribed for osteoporosis, prostate conditions and erectile dysfunction, are primarily prescribed to older people, who are already at a higher risk of vision loss.
Even some herbal medications may contribute to vision loss. For example, the tanning agent canthaxanthin has been known to cause small crystal deposits in the retina. Contact a physician immediately if experiencing any abnormalities in vision.
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Contact lenses
Contact lenses must be used correctly to prevent the wearer from contracting a rare, but serious infection. Known as acanthamoeba keratitis, the condition most often occurs in the cornea of contact lens wearers who don’t adequately clean the lenses or lens case or who expose their eyes to water while wearing their contacts.
The infection is painful and, if left untreated or undiagnosed, can lead to scarring that may eventually cause blindness. Symptoms include tearing, redness, blurry vision, swelling, a feeling that something is “in the eye,” sensitivity to light and discharge.