Prescription eyeglasses help billions of people across the world improve their vision. In fact, when a person’s vision starts to weaken, a new eyeglass prescription is often the solution. However, prescription eyeglasses cannot correct every issue, including low vision.

The National Eye Institute defines low vision as a vision problem that makes it hard for people to perform everyday activities. People with low vision may not see well enough to read, drive, recognize people’s faces, distinguish between colors, or see their television or computer screens clearly. Though low vision is a serious condition, the Cleveland Clinic notes it does not include complete blindness and can sometimes be improved with the use of visual aids. Understanding low vision and how it can affect a person’s daily life can help patients and their families confront the condition more successfully.

Are all types of low vision the same?

The NEI notes that there are different types of low vision. The four most common types of low vision are:

Central vision loss: This is marked by an inability to see things in the center of your vision.

Peripheral vision loss: This affects peripheral vision and compromises a person’s ability to see things out of the corners of the eyes.

Night blindness: A person diagnosed with night blindness will be unable to see in low light.

Blurry or hazy vision: The Cleveland Clinic notes that objects both near and far will appear out of focus person when a person is dealing blurry vision. Someone with hazy vision will feel as though his or her entire field of vision is covered with a film or glare.

What causes low vision?

The NEI notes that low vision is not caused by aging alone. However, there is a link between aging and low vision. Many of the diseases that can cause low vision are most common in older adults. In fact, the Cleveland Clinic notes low vision affects one in four adults over age 75 and one in six adults over age 45. The type of low vision a person has will depend on the disease or condition that caused it.

Many different eye conditions can cause low vision, but the NEI says the four most common are:

Age-related macular degeneration (AMD): AMD is a disease of the eye that can blur the vision people need to read and drive. AMD is slow to develop and as it progresses the blurry area near the center of vision may get bigger and things may also seem less bright than before.

Cataracts: Cataracts affect more than half of all Americans age 80 or older. The NEI notes that many people do not notice they have a cataract initially. But over time, people with a cataract may notice their vision becoming blurry, hazy or less colorful.

Diabetic retinopathy: Diabetic retinopathy affects blood vessels in the retina and can cause low vision in people with diabetes. The NEI urges anyone with diabetes to schedule comprehensive dilated eye exams at least once per year, as finding diabetic retinopathy early, even when no symptoms are present, can help people protect their vision.

Glaucoma: Glaucoma is an umbrella term used to describe a group of eye diseases that damage the optic nerve. The NEI notes that half of all people with glaucoma don’t even know they have it, which only underscores the importance of scheduling comprehensive dilated eye exams.

Low vision is a serious condition that can affect people’s ability to perform daily tasks like reading and driving. More information about low vision can be found at www.nei.nih.gov.