According to the Cleveland Clinic, nearly 3.5 million Americans aged 40 and older are considered legally blind. Per the Cleveland Clinic, “Vision loss is among the top 10 causes of disability in the U.S in adults over the age of 18.” There are hundreds of eye diseases and conditions affecting vision, but here are four of the most common that lead to vision loss in adults.*

Macular degeneration

The macula is the central part of the retina that allows us to see fine details. In macular degeneration, or age-related macular degeneration (AMD), the macula is damaged and central vision is lost. For people over age 60, AMD is the leading cause of vision loss.

There are two types of AMD.

• In wet AMD, abnormal blood vessels appear under the macula, from which blood and fluid escape that damage the macula.
• In dry AMD, the more common form of the disease, the macula thins and gradually blurs central vision.

Symptoms usually don’t appear until the disease is more advanced. They include:

• Blurry central vision
• Seeing black or dark spots in your central vision
• Straight lines appearing wavy or curved

AMD has no cure, but treatment can slow progress and prevent severe vision loss. 

Cataracts

A cataract occurs when the eye lens becomes cloudy from protein deposits. Cataracts are the main reason for blindness in the world and the leading cause of (reversible) vision loss in Americans. Cataracts can happen at any age, but are most common after 50.

Symptoms of cataracts can involve:

• Cloudy or blurry vision
• Glare surrounding lights at night 
• Poor night vision
• Sensitivity to bright light
• Requiring bright light for reading
• Changes in color perception

Over 90% of people see better after surgical replacement of their natural clouded lens with a clear artificial lens.

Diabetes-related retinopathy

The retina receives light and converts it to visual information to be sent to the brain. In diabetes, ongoing high blood sugar (glucose) can damage blood vessels supplying the retina. Most people experience no visual changes until the disease is advanced.

Symptoms of diabetes-related retinopathy include:

• Blurry or distorted vision
• New color blindness or color fading
• Difficulty seeing at night
• Seeing small dark spots or streaks
• Difficulty seeing or reading at farther distances

Treatments involve medication and surgery to repair or shrink retinal blood vessels.

Glaucoma

Glaucoma is most often caused by elevated fluid pressure inside the eye. The abnormal pressure leads to optic nerve damage that changes how visual information is sent to the brain. Often inherited, glaucoma is the leading cause of irreversible blindness if left undiagnosed and untreated.

There are two types of glaucoma.

• Open-angle glaucoma occurs gradually and there may be no visual changes until the disease is advanced.
• Closed-angle glaucoma is less common, occurs suddenly and painfully, and causes rapid vision loss and blindness if you do not get immediate medical attention.

Symptoms of advanced open-angle glaucoma most often show up as blind spots or blurriness in your peripheral (side) vision. Signs of closed-angle glaucoma often include sudden:

• Eye pressure or pain
• Severe headache
• Rainbow-colored rings around lights
• Blurred vision
• Tunnel vision 

Treatment is aimed at lowering eye pressure and involves eye drops, laser, or surgery.

Everyday eye care for optimal vision

Early detection and treatment of serious eye problems is critical for preserving vision, say Cleveland Clinic experts. They recommend that you:

• Attend regular eye exams, 
• Minimize risk factors, 
• Eat healthily, exercise, and don’t smoke, and
• Protect your eyes from strain and injury by wearing protective eyewear such as sunglasses and work goggles, using contacts properly, and avoiding excessive screen time.

“If you notice any changes in your vision, see your eye care professional,” they write. “Even if you don’t have noticeable changes in your vision, it’s important to have regularly scheduled eye exams. Some vision problems have no early warning signs.”

*Cleveland Clinic. (2022, January 14). Common Eye Diseases and Vision Problems. https://my.clevelandclinic.org/health/diseases/17130-eye-diseases