What Are the Causes of Blindness and Vision Loss?



In the “dry” form of this disease, small deposits called drusen dry out the macula – the part of the eye that gives us our central vision and allows us to see in great detail and vivid colors. In the most damaging “wet” form, abnormal blood vessels develop under the macula, causing fluid to leak or bleed.

AMD may not cause complete blindness, but it can cause loss of central vision and make it harder to see faces, driving, and other tasks. Certain vitamins and minerals, especially those found in green leafy vegetables, may lessen its effects.

Diabetic retinopathy

Diabetic retinopathy – a complication of diabetes – is extremely common: more than 2 in 5 people with diabetes develop diabetic retinopathy, according to the National Institute of the Eye of the National Institutes of Health; older Hispanics are particularly at risk.

This disease occurs when blood sugar blocks the vessels of the retina, the light-sensitive tissue at the back of the eye. It progresses in four stages and can eventually eliminate vision. It is treated with injections, laser treatment, and surgery; controlling blood sugar is the best way to reduce your risk.


More than 2.7 million Americans over 40 have glaucoma, but only half are aware of it, according to the American Academy of Ophthalmology. People over 60 (or over 40 for people of color), smokers, and people with a family history of glaucoma are at higher risk.

Glaucoma damages the nerve that transmits visual information to the brain. In most cases in the United States, the eye does not drain fluid well, which puts pressure on the optic nerve. In others, the iris blocks the drainage of fluids, increasing eye pressure.

The most common form of the disease (open-angle glaucoma) progresses slowly and without obvious symptoms at first, but can eventually cause blindness if left untreated. Treatments cannot restore lost vision, but can prevent it from getting worse. Regular exercise can also help, says Brinks. He mentions a study in which people with glaucoma rode an exercise bike three times a week for 45 minutes each time, “and the eye pressure dropped dramatically. It was a home run. ”


Cataracts are the most common eye disease in the United States, affecting more than 25 million Americans; by age 80, most people have cataracts or have had surgery to correct them. Cataracts develop when eye proteins break down and clump together, forming a cloudy area on the lens, much like fog on a window. They blur and dull vision, making reading, driving, and other activities more difficult.

They are the leading cause of blindness worldwide, but are less likely to cause blindness in this country, thanks to very effective treatments and relatively easy access to them. “It’s almost completely reversible,” says Brinks, who calls it “a medical achievement.”

Other disorders

Two other major causes of visual impairment – amblyopia (aka “lazy eye”) and strabismus, an imbalance in the positioning of the eyes – develop during infancy or childhood. Common “refractive errors” such as myopia, hyperopia and astigmatism (distorted vision at all distances) also impair vision, especially with age, and can be a major problem for those without. access to eye care. “Basic refractive error is a public health concern in this country,” says Jeff Todd, president and CEO of Prevent Blindness, an eye health and safety organization.

Prevention and treatment

Not all vision loss is preventable, and some diseases are difficult to treat. But regular eye exams can protect eye health, Todd says, allowing for critical early intervention if problems arise.

Wearing eye protection and taking other safety precautions also protects vision. And regular exercise, a healthy diet, and quality sleep are also essential. “Taking care of your body is taking care of your eyes,” says Todd.

Brinks and Todd also recommend “screen timeouts,” especially as we are spending more time on computers during the pandemic. They cite the “20-20-20” rule: every 20 minutes, look at least 20 feet from your computer screen for at least 20 seconds. “It’s good to go out and let your eyes rest with the rest of your body,” Todd says.

At a more systemic level, we can advocate for improving and advancing access to health care and for increased support for telehealth and vision health research. “If you’re lucky enough to live old enough, you’re going to experience changes in your vision,” Todd says. “That doesn’t mean that there is nothing to be done about it.”



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