Back to the articles

Genetics of Poor Vision: Is Eyesight Hereditary?

Eye Health

structure image Genetics of Poor Vision: Is Eyesight Hereditary?


If you have bad eyesight and your parents do too, you may be wondering if poor vision is genetic. In many cases, the answer is yes. Several eye conditions and diseases can cause reduced vision, and some of these are hereditary.

Conditions That Cause Bad Eyesight

The most common cause of reduced vision is uncorrected refractive error, such as nearsightedness (myopia), farsightedness (hyperopia), or astigmatism. Uncorrected refractive error is simply the need for a glasses or contact lens prescription to maintain ideal vision.

A person needs a refractive error correction when the cornea and lens in the front of the eye can’t focus light directly on the retina in the back of the eye.

Other causes of poor eyesight include:

  • Presbyopia. Also known as age-related farsightedness, presbyopia is a normal part of aging. Most people start to notice their near vision begins to blur around age 40-45.
  • Amblyopia (lazy eye). This condition develops in childhood. Amblyopia is decreased vision due to high, uncorrected refractive error; one eye crossing (strabismus) 100% of the time; or a cataract or corneal scar that is central in the eye. Amblyopia may develop in one or both eyes.

Diseases That Cause Bad Vision

Certain eye diseases can also lead to bad eyesight. The most common of these have a strong heredity and include:

  • Macular degeneration. The retina is the part of the eye that focuses images so you can see clearly. The macula is part of the retina and is responsible for sharp central vision. Macular degeneration occurs when the macula deteriorates, resulting in progressive central vision loss.
  • Glaucoma. Glaucoma encompasses a number of eye conditions that cause damage to the optic nerve. The optic nerve transmits information between the eyes and brain. Glaucoma is caused by increased pressure inside the eye. People generally don’t have visual symptoms until the eye pressure has already damaged the optic nerve. This damage can lead to blindness.
  • Cataracts. A cataract resembles a milky cloud over the eye’s lens caused by a buildup of proteins. At first, your vision may be a little hazy or blurry. Over time, the cataract blocks light from reaching the retina and causes more significantly reduced vision.

These eye diseases often happen later in life and can lead to vision impairment if they’re not treated.

Is Bad Eyesight Genetic?

In many cases, poor eyesight is genetic. There are specific genetic markers present in people who have common refractive errors, such as nearsightedness, farsightedness or astigmatism. If you have these markers, you’re nearly 10 times more likely have these vision problems than people who don’t have family heredity.

For example, a recent study has shown there is a 30% greater chance that you’ll be nearsighted if both of your parents are nearsighted. If only one of your parents is nearsighted, you have a 20% greater chance of being nearsighted too.

Environmental Factors That Cause Bad Eyesight

Genetics are not the only contributors to reduced vision. Environmental factors can also cause eye problems:

  • UV radiation. Overexposure to the sun’s UV rays can lead to cataracts and macular degeneration.
  • Smoking. Smoking contributes to overall poor health and may influence your eye health. People who smoke are more likely to develop cataracts and macular degeneration.

How To Treat Bad Eyesight

The treatment for poor vision depends on the cause your vision problem:

  • Refractive errors. Nearsightedness, farsightedness and astigmatism can be corrected with eyeglasses, contact lenses or corrective laser procedures.
  • Amblyopia. Amblyopia may be treated with a refractive error correction in addition to wearing an eye patch over the better seeing eye. The aim is to train the brain to develop the the weaker one. Topical eye drops, which blur the better seeing eye, are another possible treatment for amblyopia.
  • Age-related macular degeneration (AMD) . AMD does not have a cure. The most common form of AMD, dry AMD, has no direct treatment options. Vision aids can be prescribed to improve reduced vision. The more serious form of AMD, wet AMD, can be treated with intravitreal (within the eye) injections. You can reduce your risk of developing AMD by eating a healthy diet, exercising, taking vitamins and protecting your eyes from the sun.
  • Glaucoma. Treatment of glaucoma focuses on maintaining vision at the time of diagnosis. Early diagnosis is crucial in order to maintain a patient’s optimal vision and minimize progressive vision loss. Medicated eye drops, laser treatment and surgery are options for treating glaucoma.
  • Cataracts. Cataract extraction surgery is standard care for improving vision due to the development of cataracts. During surgery, the cloudy lens in your eye is replaced with an artificial lens. Cataract surgery is an efficient procedure with very successful outcomes.

Can You Prevent Bad Eyesight?

Genetics and environment contribute to the development of uncorrected refractive errors and the development of certain vision conditions. There are things you can do to help prevent conditions and diseases that can lead to poor eyesight and vision loss:

  • Preserve your vision and eye health by eating a balanced diet, drinking plenty of water and getting a good night’s sleep.
  • Prevent certain eye diseases by eating lots of orange fruits and vegetables (such as carrots) and fish, and by protecting your eyes from the sun’s UV rays.

The best way to take care of your eyesight and eye health is to see your eye doctor for regular eye exams. The earlier vision conditions and diseases are diagnosed, the better chance you have of maintaining optimal vision and eye health.