Over 3 million people (40+) in the U.S. are legally blind or have low vision, which means they have a best-corrected visual acuity below 6/12 (greater than 20/40). The primary causes of poor vision and blindness in America are connected to certain eye conditions and diseases. These include cataracts, glaucoma, diabetic retinopathy, and age-related macular degeneration, among other eye disorders.
Many people also have a refractive error, such as astigmatism, nearsightedness (myopia), farsightedness (hyperopia), presbyopia, or a combination. Eyeglasses, contact lenses, or LASIK eye surgery are necessary to correct mild to severe refractive errors.
There are hundreds of eye disorders and conditions that can cause low vision, blindness, eye discomfort, and/or other life-altering conditions. Some eye conditions, on the other hand, may not cause vision loss but can result in vision and eye irregularities.
Some common eye problems (that range from mild to severe) include:
Glaucoma is a group of eye conditions that damage your optic nerve, which is essential for good health and vision. These conditions are usually caused by abnormally high pressure in your eye and are the leading cause of blindness in older people. Treatment options include lowering your eye pressure, eye drops, medications, surgery, and laser treatment.
Cataracts occur when the lens of a person’s eye becomes cloudy, rather than clear. Most types of cataracts form slowly over many years. The primary symptom of this condition is blurry vision, like looking out of a cloudy window. Treatment includes cataract surgery, which consists of replacing the lens with an artificial, clear lens.
Diabetic eye diseases affect people with diabetes, which is a group of diseases that result in high blood sugar. Diabetes can damage your eyes over time and cause vision problems, even blindness. Some common diabetes-related eye diseases include cataracts, glaucoma, diabetic retinopathy, and diabetic macular edema.
Keratoconus is a continually developing eye disease that leads to a bulging cornea (the thin film covering your eye). Over time, the cornea starts to form into a cone shape, which diverts the light entering your eye and results in distorted vision. Surgery is necessary to cure this condition.
Macular degeneration is an age-related eye condition that results in loss of the central vision of your eye (macula). Blurred vision or vision loss are the primary symptoms of this condition. Treatment includes taking a combination of certain minerals and vitamins (AREDS formula) or undergoing surgery.
Retinitis is inflammation of the retina, a thin layer of tissue lining the back of the eye. This condition can permanently damage the retina and cause blindness. An ophthalmologist can help diagnose retinitis during an eye exam.
Retinal detachment can be caused by injuries, retinal inflammation, posterior vitreous detachment, tumors, and some eye surgeries, causing peripheral loss of vision over time.
Eye styes are painful, red bumps that appear on the edge of your eyelid. They look similar to a pimple or boil and are usually filled with pus. In some cases, a stye can form on your inner eyelid. Styes are relatively harmless and disappear on their own within a few days to a week. Treatment includes applying a warm washcloth to the stye to relieve any discomfort or pain.
Unlike a stye, a chalazion is a painless bump that develops in the oil gland of your eyelid. It typically forms if this gland gets clogged. If the chalazion is large, you may need to get it removed by a doctor or apply hot compresses to it. However, most minor cases resolve on their own within a few days.
Uveitis is a form of eye inflammation that affects the middle layer of tissue in your uvea (eyewall). The symptoms of this condition often come on suddenly and get worse quickly. Indicators of uveitis include eye pain, blurred vision, and eye redness.
Visual contrast sensitivity is the ability to differentiate between an object and what is behind it. However, contrast sensitivity is not the same as visual acuity, which measures how clear your vision is at a certain distance.
People with poor contrast sensitivity tend to have difficulties driving at night or in harsh weather conditions, such as fog, rain, and snow. These individuals also generally have trouble locating objects with a similar color background, reading newspapers, stepping off curbs, and distinguishing facial features on other people.
Someone who is color blind has trouble seeing the difference between a green object and a red object. In some cases, they also have difficulty seeing yellows or blues (rare). Currently, there is no cure for color blindness. But fortunately, there are special lenses that can improve color vision and reduce any deficiencies.
The cornea is a transparent tissue that covers the front of your eye. It helps focus the light entering your eye. Corneal ectasia is a rare, sight-threatening condition that can cause permanent damage to the cornea. Keratoconus, pellucid marginal degeneration, keratoglobus, and laser eye surgery can all cause this condition.
When one eye is misaligned, both eyes cannot focus in the same direction. To avoid double vision, your brain tries to tune out what the misaligned eye is seeing. Some children have intermittent strabismus, which means the eye turn is not present all the time.
You can develop dry eyes when your eyes are not making enough tears or if your tears are of poor quality. A healthy tear film is essential for eye health because your tears flush out irritants, protect against eye infections, help you see clearly, and lubricate your eyes. There are a variety of treatment options available for dry eye syndrome, including lubricating drops, supplements, and heat compresses, among others.
The main symptom of ptosis is a droopy upper eyelid. There are many potential causes of ptosis. In most cases, the underlying cause is due to a defect in the muscles that control your eyelid movements. If the condition is mild and there is no correlated disease, treatment may not be needed. Some people seek treatment for cosmetic reasons or if they have vision problems due to the droopy eyelid(s).
After you spend a long time looking at your smartphone, computer, or tablet, you may develop digital eye strain. This is a common condition that can cause eye strain, fatigue, blurry vision, difficulty refocusing between near and far distances, tired eyes, double vision, dry eyes, and headaches, among other symptoms. Fortunately, there are many ways to prevent digital eye strain, such as improved posture, anti-glare protection, and eye lubrication.
Blepharitis is a condition that causes your eyelids to become inflamed and often leads to dandruff-like scales and debris at the base of the eyelashes. Blepharitis is very common in people who have rosacea — a skin condition that causes the oil glands in your face, nose, and eyelids to clog.
A corneal ulcer is an open wound that forms on your cornea (the transparent outer layer of your eye). Most corneal ulcers are painful because the cornea has the most nerve fibers than any other part of your body. Treatment for this condition focuses on treating the underlying cause of the ulcer, rather than the ulcer itself.
Eye floaters are harmless, common spots you see in your field of vision. Floaters are a normal part of aging, but younger people can experience them as well. If your eye floaters are bothering you, there are treatment options available. In most cases, optometrists recommend not treating floaters unless they interfere with your vision significantly.
A pterygium is a benign (non-cancerous) fleshy growth that forms on the front of your eye. The cause of surfer’s eye is unknown, but most research points to ultraviolet (UV) radiation from the sun as the main factor, especially if you are around water often. Most pterygia do not require treatment. Instead, your eye doctor may recommend tracking the growth of the condition yearly.
Pink eye (conjunctivitis) is an inflammation of the conjunctiva, which is the thin layer of tissue that covers the whites of your eye and lines the inner portion of your eyelids. Pink eye can be caused by a viral infection, bacterial infection, or allergies. Treatment depends on the underlying cause, but the condition generally resolves on its own without treatment.
Amblyopia (lazy eye) causes reduced vision as a result of irregular visual development. A lazy eye typically develops in just one eye but can develop in both. Amblyopia often starts between birth and early childhood, which is a crucial time for proper vision development. Children who get amblyopia treatment at a young age have a better visual outcome, but the condition can also be treated later in life.
Red eyes could be a symptom of another eye condition, such as conjunctivitis (pink eye) or sun damage caused by not wearing sunglasses.
Some common eye problems (that range from mild to severe) include:
“Common Eye Disorders.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 29 Sept. 2015, www.cdc.gov/visionhealth/basics/ced/index.html.
“Glossary of Common Eye & Vision Conditions.” Glossary of Eye and Vision Conditions, www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions.