Is bad eyesight genetic?

Poor vision is a common concern for many people around the world. Understanding what factors lead to vision problems can help you maintain your eye health and prevent worsening vision or eye-related issues. 

Read on to learn about eye conditions that cause poor vision, hereditary eye conditions, and other factors that can affect your eyesight.

Is poor vision hereditary?

Yes, poor vision can be inherited, as many common vision problems tend to run in families. If one or both of your parents have vision issues, you may be at a higher risk of developing them as well. 

While genetics can play a role in whether or not you have poor vision, several other things can contribute to impaired eyesight, like trauma, environmental factors, age, and systemic health problems.

The term “poor vision” is often equated to how well you can see. But vision problems can be associated with other symptoms such as pain, dry eyes, double vision, and more. If you experience any eye or vision concerns, see an eye doctor promptly for further evaluation.

Eye conditions that cause poor vision

When you think of bad eyesight, conditions like refractive errors or eye movement disorders might come to mind. These conditions can be associated with genetics, meaning you inherited them from one or both of your parents. 

Refractive errors

Refractive errors are eye conditions that make it hard to see at a short or long distance. Common refractive errors include:

• Myopia (short-sightedness) – When nearby objects appear blurry
• Hyperopia (long-sightedness) – When distant objects appear blurry
• Astigmatism – When both nearby and distant objects appear blurry or warped[1] 

Additional signs and symptoms of refractive errors can include eye strain, halos or rings surrounding lihgt, double vision, and squinting to try and see clearly.  Refractive errors are commonly treated with eyeglasses or contact lenses.

Strabismus (crossed eyes)

Strabismus is when the eyes do not align. When one eye looks straight ahead, the other is turned in another direction. The types of strabismus include:

• Esotropia – When one eye turns inward
• Exotropia – When one eye turns outward
• Hypertropia – When one eye looks upward
• Hypotropia – When one eye looks downward[3] 

Approximately 30% of children with strabismus have a family history of these types of issues.. Eyeglasses, contacts, eye patching, surgery, or other options may be used to treat the condition. 

Amblyopia (lazy eye)

Amblyopia occurs when vision in one eye does not develop properly during childhood. This lack of visual development disrupts the communication between the brain and the eye, resulting in decreased vision in the affected eye. Both eyes may be involved in some cases, though this is rare. 

There are several risk factors for amblyopia, one of which is a family history of the condition. 

Genetic eye diseases can cause bad eyesight

Over 350 eye diseases are linked to gentic factors. Some of these can cause eyesight to worsen over time, leading to blindness, blurred vision, and other issues. 

Some eye diseases may run in a family and can develop at a younger age. Other conditions such as glaucoma, cataracts, and age-related macular degeneration (AMD) are more likely to develop as you get older.

Glaucoma

Glaucoma is a disease that damages the optic nerve. It often occurs when fluid inside the eye fails to drain properly, raising the pressure within the eyeball. If left untreated, glaucoma can cause vision loss, eye pain, and other symptoms. It may lead to blindness without proper management.

While various factors can contribute to glaucoma development, most cases are caused by increased eye pressure from fluid buildup. If the disease runs in your family, you have a greater chance of developing it.

Cataracts

Cataracts develop when changes in the eye’s crystalline lens cause cloudy areas to form. The condition can progress over time, leading to blurry or foggy vision. Without treatment, cataracts can eventually result in vision loss.

While they’re more common in older individuals, cataracts can occur at any age. If someone in your family has cataracts, it increases your chance of developing them. 

Age-related macular degeneration (AMD)

The macula is the structure in the eye that gives you sharp central vision. If the macula is damaged, your central vision can become blurred. Aging can cause damage to the macula, resulting in a condition called age-related macular degeneration. Your chances of developing the disease are higher if it runs in your family. 

Environmental factors can lead to bad eyesight

While many eye issues are impacted by genetics, you may be at a higher risk of developing some conditions because of environmental factors. Overexposure to ultraviolet (UV) light can damage the eyes and cause problems with your vision. Too little sunlight exposure can also affect the development of the eyes during childhood, according to some experts.

Ultraviolet exposure

Harmful ultraviolet radiation can affect your eyes in more ways than one. In some cases, it can lead to poor vision or cause your vision to worsen.

Chronic exposure to UV rays can affect proteins in the eye’s lens. Cataracts can form as a result, leading to blurred vision and poor eyesight. 

UV exposure can also increase the risk of eyelid cancers, such as squamous cell carcinoma and basal cell carcinoma. Eyelid cancer can cause swelling or other changes to the eyelid that could obstruct your vision or cause other vision issues.

Studies have suggested a link between UV exposure and an increased risk of age-related macular degeneration. Research to confirm this association is ongoing.

It’s crucial to protect your eyes whenever you’re exposed to the sun’s harmful rays. Be sure to wear sunglasses with lenses that offer 100% UVA-UVB protection along with a wide-brimmed hat. Doing so is the easiest way to help prevent UV-related eye problems like those mentioned above.

Lack of outdoor exposure

Too little exposure to sunlight may contribute to the development of myopia. According to several international studies, the rate of myopia among children who spend more time outdoors is lower compared to those with less outdoor exposure.

Experts think lower myopia rates might be linked to exposure to natural light, which increases the release of dopamine in the eye. Dopamine is a chemical that helps regulate eye growth. Studies suggest these factors may affect eye development in children and potentially lower their risk of developing myopia.

Although sunlight exposure may lower the risk of myopia, children (and adults) should always use proper UV eye protection when spending time outdoors. 
 

Other factors may cause poor vision

Poor eyesight can occur as a result of trauma, age, and lifestyle factors in some cases. It can also be secondary to other diseases. These factors are discussed below.

Smoking and vaping

Lifestyle factors like smoking and vaping can be damaging to various aspects of your health, including your vision. Both can raise your risk of developing cataracts, AMD, dry eye, and issues with the optic nerve. Smokers who have conditions such as Graves’ disease or diabetes may face increased problems with their vision and overall health.

Age

Presbyopia (age-related farsightedness) is a normal part of aging. Around age 40, the eye’s crystalline lens begins to lose its flexibility. As a result, it becomes more difficult to see things up close, like books, menus, or phone screens. You may experience blurred vision or eye strain when looking at nearby objects. Presbyopia can be treated with reading glasses, contact lenses, or other options.

Some eye conditions are influenced by both age and genetics. This includes cataracts, AMD, glaucoma, and diabetic retinopathy. Existing eye conditions and health problems that affect the eyes can sometimes worsen with age. Be sure to attend routine eye exams to monitor your eye health and receive any additional care you may need.

Trauma

Eye injuries or trauma can cause temporary or long-term vision problems. Should you experience such an injury, it’s crucial to have your eye(s) examined immediately to determine any treatment needs and achieve the best possible outcome.

 Some examples of trauma include:

• Chemical burns
• Sports-related eye injuries
• Blunt trauma
• Scratching or poking the eye
• A foreign body entering the eye

Effects you may experience because of eye trauma include:

• Pain
• Swelling
• Bleeding
• Double vision or blurred vision
• Light flashes or black spots in your vision
• Debris or objects becoming stuck in the eye
• An altered appearance of the eye
• Trouble moving the affected eye

Eye injuries can also increase your risk of developing certain eye conditions like cataracts.

Other conditions

Finally, poor vision may occur when an underlying health condition is present. Some diseases that can affect the eyes include:

• Diabetes
• High cholesterol
• High blood pressure
• Heart problems
• Stroke
• Brain tumors
• Thyroid disease
• Rheumatoid arthritis
• Multiple sclerosis (MS)
• Lupus
• Giant cell arteritis
• Albinism

If you have any of these conditions or one not mentioned here, and you notice any vision problems, visit your eye doctor promptly. You may need additional treatment to ensure proper care and prevent further complications. 

It’s also important to have your eyes examined regularly to identify any eye or vision concerns as early as possible. Existing Lenstore customers can get a free eye test with our trusted partner, Vision Express — simply book an eye appointment online.

SOURCES:

1. Refractive errors. National Eye Institute. November 2023.
2. Strabismus (eye misalignment). Cleveland Clinic. June 2023.
3. Amblyopia (lazy eye). Moorfields Eye Hospital. NHS Foundation Trust. Accessed August 2024.
4. Hereditary ocular disease. Research to Prevent Blindness. Accessed August 2024.
5. Glaucoma. National Health Service. February 2021.
6. Age-related cataracts. National Health Service. December 2020.
7. Age-related macular degeneration (AMD). National Eye Institute. June 2021.
8. Environmental impact on ocular health. EyeWiki. American Academy of Ophthalmology. April 2024.
9. Protecting your eyes from the sun’s UV light. National Eye Institute. July 2022.
10. Eyelid cancer. Mays Cancer Center. UT Health San Antonio MD Anderson Cancer Center. Accessed August 2024.
11. UV radiation linked with early AMD onset. Review of Optometry. September 2023.
12. Lifetime ambient ultraviolet radiation exposure and incidence of age-related macular degeneration. Retina. January 2024.
13. The influence of the environment and lifestyle on myopia. Journal of Physiological Anthropology. January 2024.
14. How do smoking and vaping damage the eyes? EyeSmart. American Academy of Ophthalmology. February 2024.
15. Presbyopia. Cleveland Clinic. July 2023.
16. Common age-related eye problems. Cleveland Clinic. May 2024.
17. Eye injury. Cleveland Clinic. May 2024.
18. 20 surprising health problems an eye exam can catch. EyeSmart. American Academy of Ophthalmology. April 2024.
19. Albinism. National Health Service. September 2023.