Causes of Low Vision and How They Affect Your Eyes

Low vision is a condition that causes permanent changes to your eyesight, making everyday tasks more difficult even when using prescription glasses or contact lenses. People with low vision may struggle to read, drive, recognize faces, or perform routine activities. According to the World Health Organization, low vision is classified by visual acuity:

Moderate Low Vision: Best corrected vision between 20/70 and 20/160
Severe Low Vision: 20/200 or worse
Profound Low Vision: 20/500 to 20/1000
Near-Total Low Vision: Less than 20/1000

Several eye conditions can lead to low vision, and understanding them is key to protecting your remaining sight.

Diabetic Retinopathy

Diabetic retinopathy is a complication of diabetes that affects the blood vessels in the retina, the light-sensitive tissue at the back of your eye. High blood sugar can damage these vessels, causing leaks or abnormal blood vessel growth. This can interfere with vision and, if left untreated, lead to permanent vision loss. Maintaining good blood sugar control and regular eye exams is critical for preventing complications.

Glaucoma

Glaucoma occurs when increased pressure inside the eye damages the optic nerve, which transmits visual information from the eye to the brain. This damage can create blind spots and, in severe cases, total vision loss. Glaucoma often develops gradually without noticeable symptoms, making annual eye exams essential for early detection. During your visit, your optometrist will check eye pressure and examine the optic nerve for signs of damage.

Torn or Detached Retina

A retinal tear or detachment is a medical emergency. Symptoms may include sudden blind spots, flashes of light, or the sensation of a dark curtain over part of your vision. Retinal detachment can result from eye injuries, aging, or certain eye conditions. Prompt treatment is essential to prevent permanent vision loss.

Macular Degeneration

Age-related macular degeneration (AMD) affects the central part of the retina, called the macula, causing blurred or blind spots that make reading, driving, and recognizing faces difficult. There are two forms:

Dry AMD: The macula thins and accumulates yellow deposits (drusen). Currently, there is no treatment.
Wet AMD: Abnormal blood vessels grow under the macula and leak fluid. Treatments such as injections or laser therapy may slow progression.

Early detection and monitoring are crucial for managing AMD effectively.

Cataracts

A cataract occurs when the normally clear lens of the eye becomes cloudy, reducing vision clarity and causing glare or halos around lights. Cataract surgery, which replaces the clouded lens with an artificial lens implant, usually restores vision. However, patients with additional eye conditions like macular degeneration or diabetic retinopathy may still experience some vision limitations after surgery.

Retinitis Pigmentosa

Retinitis pigmentosa (RP) is an inherited condition in which cells in the outer retina gradually degenerate. This leads to a loss of side (peripheral) vision and difficulty seeing in low-light conditions or at night. RP often progresses to legal blindness by age 40. While there is currently no cure, low vision aids can help maximize remaining sight.

Living with Low Vision

If you have low vision, specialized low vision aids and adaptive tools can enhance your quality of life. Your optometrist can help you find devices such as magnifiers, high-contrast materials, or electronic aids to make daily activities easier and safer.

Regular eye exams and early intervention are key to preserving vision and maintaining independence. Contact our office to schedule an appointment and explore the best options for managing low vision.