How does albinism affect vision?

Albinism is a rare genetic condition that blocks the body’s ability to produce or distribute melanin, the pigment that provides color to the skin, hair and eyes. Melanin is crucial to the development of the optic nerves, and mild to serious vision problems can result from a lack of this pigment.

Most forms of albinism cause the skin, hair and eyes to be pale or white. But when only the eyes are affected, the condition is called ocular albinism.

People with albinism are at higher risk of developing vision issues because their lack of pigment prevented their eyes from developing normally in utero and through infancy. Common eye problems include:

• Light sensitivity (photophobia)

• Refractive errors (astigmatism, myopia, hyperopia)

• Nystagmus – Involuntary movement of the eyes (this can lead to abnormal head positioning)

• Strabismus – Misalignment of the eyes

• Foveal hypoplasia – A retinal disorder that reduces visual acuity

• Optic nerve misrouting – Signals from the retina to the brain don’t follow the normal paths 

• Iris transillumination – Lack of pigment allows light to enter through the iris, not just the pupil

• Monocular vision – Absence of stereo (or binocular) vision, the ability of the eyes to work together

• Low vision – Best corrected visual acuity of 20/70 or worse

In some cases, eye-related symptoms can actually lead to a diagnosis of albinism where it may not have been considered previously. 

It may be possible to correct some albinism-related vision problems with eyeglasses or contacts (at least in part). However, many of these issues stem from having abnormally developed retinas and misrouting optic nerves, problems that can’t be fixed with surgery or glasses.

That doesn’t stop many people with albinism from leading normal lives. Some can see well enough to drive a car, and those with more severe impairments learn to use the sight they have to perform their everyday activities.

An estimated one in 18,000 to 20,000 people in the U.S. has some type of albinism. While albinism is generally rare, some forms of the condition are extremely rare. All types can affect a person’s vision.

Oculocutaneous albinism

The most common form, oculocutaneous albinism (OCA) , occurs when the tyrosinase (TYR) gene mutates, resulting in a person having an absence or reduced amount of melanin (color-providing pigment).

With OCA, both parents must carry the albinism gene for their child to inherit the condition. When both parents are carriers, a child has a one-in-four chance of being born with and affected by OCA. If only one parent has this albinism gene, the child won’t be born with OCA but they will have a 50% chance of carrying the albinism gene.

OCA often causes the skin and hair to be pale or white, though it can present differently based on the subtype. Eye color is also affected, with eye shade ranging from light pink or red to lighter shades of more typical eye colors (with blue being most common). OCA also makes the skin and eyes highly vulnerable to UV damage and causes retina developmental problems.

Seven subtypes of OCA have been identified to date (OCA1 – OCA7), classified generally based on a person’s level of pigment and visual impairment. For example, someone with OCA1 has zero melanin and very low vision, and people with higher-numbered subtypes have a bit more pigment (possibly even dark hair) and slightly better vision.

Since albinism results from genetic mutations, a DNA test can confirm which type of OCA a person has if needed.

Ocular albinism

Ocular albinism (OA) is the other main form of albinism. Unlike OCA, it only affects the eyes. It is also much less common than OCA, affecting only around one in 60,000 males and even fewer females.

Ocular albinism affects only the eyes, not the skin or hair. Ocular albinism reduces coloring in the iris and affects proper development of the retina.

People with OA may have light sensitivity, nystagmus, strabismus and depth perception issues. Their visual acuity is typically lower than normal, ranging from 20/60 to 20/400.

Other conditions associated with albinism

In some cases, albinism may be present alongside another rare or similar condition, or even act as an indicator of the other’s presence. These include:

• Hermansky-Pudlak syndrome (HPS) – Associated with bruising and bleeding, HPS is also considered a syndromic or less common form of albinism

• Chediak-Higashi syndrome (CHS) – CHS is considered a less common, syndromic form of albinism linked to infection susceptibility

• Angelman syndrome (AS) – Similar gene structure to albinism

• Prader-Willi syndrome (PWS) – Similar gene structure to albinism

• Griscelli syndrome – Symptoms include light skin and hair, similar to albinism

Depending on the type, people with albinism often have light or white hair, pale or fair skin, and pale or light-colored eyes. Ranging from light pink to light blue, eye color varies in people with albinism depending on which type they have.

For example, people with OCA1 type A have a complete absence of melanin so their irises are typically light pink or red. Someone with a little more pigmentation (perhaps with OCA2 or higher) is more likely to have light-colored irises of a more common shade, such as blue or brown. Light blue is the most common eye color among people with albinism.

ALSO RELATED: How genetics affect eye color

It’s important to diagnose albinism early to protect your or your child’s sensitive skin and eyes, manage eye and vision problems, and make the most of low vision aids and vision rehabilitation techniques to foster and promote a sense of independence.

An albinism diagnosis may first be suspected when a parent or doctor notices the light complexion of a child’s skin or hair at home or during a well-baby exam. It’s also possible that an eye doctor will be the first to put the pieces together during a comprehensive eye exam.

If albinism is suspected, a doctor can order a genetic test to get the most accurate results regarding type and gene mutation.

There is no cure for albinism, which is a genetic condition, not a disease. However, your eye doctor may recommend treatment options to help manage or improve certain related vision issues.

Due to low or reduced melanin, people with albinism are extremely vulnerable to UV sun damage. If you or your child has albinism, stay out of the sun as much as possible. Always apply sunscreen before going outdoors and wear sun-protective clothing and hats.

To protect your eyes, make sure you wear high-quality sunglasses that block 99% to 100% of harmful UV rays.

Scientists at the National Eye Institute have recently developed a cell model that allows them to mimic the retinal pigment epithelium (RPE) of people with OCA. 

The RPE is one of the 10 layers of the retina. It lies next to the eye’s rods and cones (the light-sensing cells) and provides nourishment and support. It also aids vision by decreasing light-scatter in the retina. 

People with OCA lack pigmented RPE. Scientists think that this lack of pigment in the RPE affects the development of structures in the eye that are critical for clear vision.

The ability to mimic OCA using a cell model is an important breakthrough. It will lead to a greater understanding of how albinism leads to abnormal development of the retina, optic nerve (which carries visual signals to the brain) and fovea (the area in the retina responsible for our sharpest central vision).

An application of the knowledge gained from this research could help individuals with oculocutaneous albinism considerably. For example, if scientists confirm that foveal development is dependent on the presence of pigment in the RPE, they could, in theory, improve pigmentation in the RPE. This could lead to greatly improved visual acuity in people with OCA.

If you have albinism, visit your eye doctor and primary care physician regularly. That way, the doctor can check your visual and overall health.