Common Causes of Vision Loss

The idea of losing your vision can be scary. After all, you rely on your vision every day. In the U.S., 32.2 million adults have experienced some sort of vision loss. Around the globe, there are an estimated 285 million people with vision impairment. Among those, 39 million are blind.

Some vision loss happens suddenly. Other times, it happens gradually. Partial blindness refers to limited vision, and complete blindness or blindness is when you cannot see anything, including light. Here is information on some of the most common causes of vision loss, including cataracts, macular degeneration, diabetic retinopathy, and glaucoma.

Cataracts

A cataract is a clouding in the lens of your eye. It is the most common cause of age-related vision loss. In addition to age, diabetes, eye injury, too much sun exposure, and other factors can speed up cataract formation.

Eye surgeons can remove cataracts. Cataract surgery is one of the most common surgeries performed in the U.S. This means that cataracts can literally cloud your vision but that it doesn't have to be permanent.

Signs and Symptoms

Here are some signs and symptoms of cataracts:

• Cloudy vision
• Double vision
• Problems seeing at night or in dim light
• Problems with glare
• Reduced color intensity
• Seeing haloes around lights

Macular Degeneration

Macular degeneration is an eye disorder that affects central vision. You use your sharp central vision to see objects clearly and for everyday tasks like reading and driving. Also called age-related macular degeneration, or AMD, this eye disorder affects the macula, located in the back of the eye. The macula is part of the retina.

Macular degeneration more commonly occurs over the age of 60 and is the largest cause of vision loss in people over age 50. There are an estimated 11 million people in the U.S. living with macular degeneration. Health experts predict that number will grow with the aging of the population.

There are two types of macular degeneration: wet and dry. Wet AMD is considered more advanced disease than dry AMD. An advanced form of dry macular degeneration is called geographic atrophy. A person can have dry macular degeneration that turns into wet macular degeneration.

Both types of AMD can affect one eye or both eyes. Both wet and dry AMD can slowly or rapidly develop.

Signs and Symptoms

Dry macular degeneration:

• Blurred vision
• Difficulty reading print or seeing details
• Faded colors
• A blurred spot in the center of your vision that becomes bigger over time

Wet macular degeneration:

• A small spot in the center of your vision that comes bigger over time
• Distortion of straight lines, or straight lines may look wavy

Diabetic Retinopathy

Diabetic retinopathy can develop when you have diabetes. It happens when high levels of blood sugar damage blood vessels in the back of the eye. The blood vessels may leak, become bigger, grow new blood vessels, or close completely.

There are two types of diabetic retinopathy. Non-proliferative diabetic retinopathy is the earlier stage, and proliferative diabetic retinopathy is the more advanced stage. However, both can have serious effects on vision. There are more than 7.7 million people in the U.S. living with diabetic retinopathy.

Signs and Symptoms

Diabetic retinopathy may not always have signs. That is why regular eye checks are important, especially when you have diabetes. Some signs of diabetic retinopathy include:

• Blurry vision or vision that sometimes is clear and sometimes blurry
• Having blank or dark areas in your vision
• Having less color intensity in your vision
• Poor vision at night
• Seeing more floaters

Glaucoma

Glaucoma refers to several eye diseases that cause damage to the optic nerve, located in the back of the eye. That damage can cause vision loss or blindness. There are several types of glaucoma. The most common type in the U.S. is open-angle glaucoma, or OAG. There are more than 3 million people in the U.S. living with OAG.

Glaucoma becomes more common with age, particularly over age 60. It also is more common in Blacks, Hispanics, or those with a family history of glaucoma.

Signs and Symptoms

Initially, glaucoma may not have any symptoms. This is why regular eye exams are important, especially as you get older. However, the most common symptom of OAG is the loss of your side, or peripheral, vision.

Another type of glaucoma called acute angle-closure glaucoma requires emergency treatment from an eye doctor. Symptoms of acute angle-closure glaucoma include:

• A red eye
• Blurry vision
• An upset stomach or nausea
• Severe eye pain

Other Causes of Vision Loss

Although cataracts, macular degeneration, diabetic retinopathy, and glaucoma are the most common causes of vision loss, there are other vision loss culprits. Those include:

• Dry eye
• Eye injury
• Congenital causes: A vision problem you've had since you were born
• Lazy eye
• Presbyopia: A normal change to your ability to see close-up objects in middle age
• Retinal detachment
• Retinopathy of prematurity: Can occur in premature babies when the blood vessels in the eye are not matured
• Severe eye infection
• Strabismus: An imbalance of the positioning of the eyes
• Stroke
• Thyroid eye disease
• Trachoma: Caused by a specific bacterial infection. It is more common in developing countries. It is the most common infectious cause of blindness around the globe.
• A tumor in or around the eye
• An uncorrected refractive error

Diagnosing the Cause of Vision Loss

Any time you have a change to your vision, you should make an appointment with an eye doctor. Many times, the cause could be as simple as a change to your refractive error, and perhaps you need new glasses or contact lenses. Sometimes, however, it could mean there is an eye disorder that requires treatment.

An eye doctor such as an optometrist or ophthalmologist will perform various tests to examine your vision loss. These could include:

• Comprehensive eye exam
• Retinal exam: This is performed with drops that dilate, or widen, the pupil. This helps the doctor to see the retina in the back of the eye.
• Visual field test: This assesses the vision you have in the eye and measures any blind spots.

Other tests performed will be specific for the potential cause of vision loss.

A Word From Verywell

Although vision loss is worrisome, there are ways to help prevent it. The best way to help lower your chances of vision loss is to schedule regular eye exams. Ask your eye doctor how often you should be examined. Another preventive move is let an eye doctor know if or when you experience any changes in your vision.

General healthy lifestyle recommendations, such as eating more fruits and vegetables, avoiding smoking, and getting regular physical activity also are helpful for the eyes as well as the rest of the body.

If you already have experienced vision loss, there often are treatments available to help stave off further vision loss. Talk to your eye doctor to find out which treatments are best suited for you.