Your kids inherit more than hair color and musical or athletic ability from you. The genes you pass on to your children may also affect their eyes.
Your Genes Help Determine Your Children's Eye Color
Eye color is inherited as a result of dominant and recessive genes that control the amount of melanin in your irises. Your irises appear brown due to a high amount of the pigment, while lower amounts result in hazel, blue or green eyes.
Did you learn that two blue-eyed parents couldn't possibly have a brown-eyed child during high school biology class? Those genetic trait charts the teacher distributed offered a simple way to understand how recessive and dominant genes affect high color but didn't necessarily provide a complete picture of the process. According to Genetics Home Reference, multiple genes play a role in eye color, which means brown-eyed parents can occasionally produce a blue-eyed child.
If You Need Glasses, Your Children May Too
Both hyperopia (farsightedness) and myopia (nearsightedness) can be inherited. Hyperopia occurs when the eyeball shortens from front to back, which causes light rays to focus behind the retina. When this occurs, your child can see objects in the distance clearly but will have difficulty seeing close objects. The opposite problem occurs in myopia. Because the eyeball is too long, light rays focus slightly in front of the retina. If your child has myopia, he or she will have no trouble reading or seeing near objects, but will notice that distance vision is blurry.
Genetics isn't the only factor that influences myopia, a refractive error that affects 30 percent of Americans, according to the American Optometric Association. Children who spend more time reading or participating in other activities that force the eyes to focus on near objects may be more likely to become nearsighted. Although it's not always possible to prevent myopia, the risk may be reduced if your child spends more time outdoors and participates in activities and sports that require looking into the distance.
Lazy Eye and Crossed Eyes Can Be Inherited
If you or a relative had amblyopia (lazy eye) or strabismus (crossed eyes) as a child, your children may be more likely to develop the conditions. In amblyopia, one eye "turns off," which can create a number of problems for kids, such as blurred vision, double vision and poor depth perception. Strabismus occurs when the eye muscles fail to keep the eyes properly aligned. Children who have strabismus are more likely to eventually develop amblyopia if they don't receive treatment. Fortunately, prompt treatment can help improve both conditions.
Certain Eye Diseases and Conditions Tend to Run in Families
Some eye diseases also have a genetic component. In some cases, your child may be diagnosed with the same disease you have. In diseases caused by recessive genes, both parents carry a copy of the gene, although they don't suffer from the disease themselves. Common inherited eye diseases include:
- Albinism. Albinism causes the irises to appear white or pink due to a lack of pigmentation throughout the body.
- Cataracts. Cataracts can be inherited and may be present at birth in some children. Cataracts occur when the clear lens in the eye becomes cloudy.
- Color Blindness. Children who have color blindness can't identify certain colors, such as red, green, blue or yellow. The condition affects more boys than girls
- Glaucoma. Glaucoma occurs when the pressure inside the eye rises to dangerous levels, which can cause permanent vision loss. If someone in your family has open-angle glaucoma, your child may be more likely to develop the disease.
- Marfan Syndrome. Although Marfan syndrome isn't strictly an eye disease, the inherited condition can affect the eyes. Marfan syndrome increases the risk of myopia and dislocation of the eyes' lenses.
- Nystagmus. Rapid eye movements are the hallmark of nystagmus, another inherited eye condition. Because the eyes frequently move up or down or from side to side, reading can be difficult.
- Retinitis Pigmentosa. Retinitis pigmentosa causes deterioration of the retina. In the early stages, the disease causes difficulty with night vision and the loss of peripheral vision. Vision continues to deteriorate as the disease progresses.
Thanks to regular eye examinations, many eye conditions and refractive errors can be diagnosed and successfully treated. If you're concerned about your child's vision, or if it's been a while since their last vision exam, give us a call.
Sources:
American Optometric Association: Myopia
American Academy of Ophthalmology: Farsightedness: Causes of Hyperopia, 3/10/14
https://www.aao.org/eye-health/diseases/hyperopia-farsightedness-causes
Genetics Home Reference: Is Eye Color Determined by Genetics?
https://ghr.nlm.nih.gov/primer/traits/eyecolor
Cleveland Clinic: Inherited Eye Disease
https://my.clevelandclinic.org/health/diseases/17130-inherited-eye-disease
Glaucoma Research Foundation: Are You At Risk For Glaucoma
https://www.glaucoma.org/glaucoma/are-you-at-risk-for-glaucoma.php
American Foundation for the Blind: Glossary of Eye Conditions
http://www.afb.org/section.aspx?SectionID=63&DocumentID=2139&rewrite=0