Down syndrome and the eyes
Each year, between 3,000 to 5,000 children around the world are born with Down syndrome — a condition where a person has an extra copy of chromosome 21 in their genes. This can impact the normal development of the body, brain and eyes.
Because of that extra chromosome, people with Down syndrome have an increased risk of developing certain eye problems, such as cataracts (clouding of the eye’s natural lens), nystagmus (uncontrollable eye movements) and blepharitis (eyelid inflammation).
They are also more likely to experience other eye or eyesight issues, including refractive errors (such as farsightedness or nearsightedness), strabismus (crossed or misaligned eyes) and keratoconus (cone-shaped bulging of the eye's cornea).
While early and routine eye examinations are essential for everyone, they are very important for people who have Down syndrome. Eye exams can help eye doctors recognize the symptoms of certain conditions sooner and, if treatment is needed, start it as early as possible.
The National Down Syndrome Society recommends that children born with Down syndrome have their first eye exam at birth. They should be closely monitored with a follow-up eye exam at six months or as recommended by their doctor.
Common eye problems in individuals with Down syndrome
A person who has Down syndrome has an increased risk of developing several different eye conditions, some of which are more serious than others. The good news is that many of these eye issues can be treated to help correct or improve the condition.
Refractive errors
One of the most frequent eye problems in children with Down syndrome is refractive errors. A refractive error occurs when the eye's ability to focus light on the retina is impaired due to irregularities in the shape or curvature of the cornea, lens or overall length of the eyeball. This results in light not landing directly on the retina — the light-sensitive membrane at the back of the eye — causing blurry vision.
There are four main types of refractive errors:
- Hyperopia (farsightedness) – Close objects appear blurry, while distant objects look clear. In severe cases, both distance and near vision can be blurry.
- Myopia (nearsightedness) – Distant objects appear blurry, while close objects look clear.
- Astigmatism – An irregularly shaped cornea or lens causes blurry vision both close up and far away.
- Presbyopia (age-related loss of near vision) – The eye’s lens gradually loses flexibility with age, making it difficult to focus on close objects.
Common symptoms of refractive errors include:
- Blurry vision
- Double vision
- Squinting or narrowing the eyes to see better
- Sore or tired eyes
- Headache
- Focusing issues when reading or using digital screens
If left untreated, these symptoms can have a negative impact on a person’s ability to read, write and work. They can also lead to problems learning in school, as well as mobility and social issues.
Fortunately, there are a number of options available to correct refractive errors and improve eyesight in those with Down syndrome, such as:
- Eyeglasses
- Contact lenses
- Corrective surgery (such as LASIK)
READ MORE: Refractive errors and refraction: How the eye sees
Strabismus (eye misalignment)
As many as 5% to 47% of individuals with Down syndrome have strabismus, a condition where the eyes are misaligned.
There are four main types of strabismus:
- Esotropia – Eyes turn inward
- Exotropia – Eyes turn outward
- Hypotropia – Eyes turn downward
- Hypertropia – Eyes turn upward
A common type of strabismus seen in Down syndrome is esotropia, where the eyes turn inward or become "crossed." One form — accommodative esotropia — occurs when the eyes turn inward while focusing, often due to uncorrected farsightedness.
There are a number of reasons why a person with Down syndrome might be affected by strabismus, such as:
- Weakened eye muscles
- Problems with the nerves that communicate with the muscles of the eye
- Neurological issues affecting the visual cortex and parts of the brain that control eye movement
- Narrowed eye cavity width (orbit)
- Retinal issues
- Accommodation weakness, where the eyes have difficulty focusing close up
Strabismus treatment options include:
- Vision therapy – Helps the eyes to realign and work together. This may involve techniques such as patching (placing an eye patch over the “good” eye) and exercises to strengthen eye muscles and enhance binocular vision and eye alignment.
- Surgery – Repositions weakened eye muscles.
- Eyeglasses or contact lenses – Correct refractive errors, decrease eye strain and align the images seen by each eye (with prism lenses in eyeglasses).
- Medications – Help relax overactive eye muscles. This may involve the use of salves, eye drops or Botox injections.
Nystagmus (involuntary eye movement)
Another common eye problem in Down syndrome is nystagmus — a condition where the eyes make uncontrollable movements side-to-side, up-and-down or around in a circular motion.
In addition to irregular eye movement patterns, other symptoms of nystagmus can impact a person’s vision and balance. These can include:
- Feeling faint or lightheaded
- Vertigo (feeling like you're spinning or whirling)
- Light sensitivity
- Problems seeing in the dark
- Blurred eyesight
In people who have Down syndrome, nystagmus is generally linked to other eye conditions, including:
- Accommodative dysfunction – Affects the ability to maintain clear vision at varying distances, particularly during near tasks
- Congenital cataracts – A type of cataract present at birth or developing shortly after
- Refractive errors – Eye conditions that cause blurry vision at various distances, such as myopia (nearsightedness)
- Esotropia – A type of strabismus or crossed eyes where one or both eyes point inward
There is currently no cure for nystagmus. However, various methods can be used to help control disease symptoms and correct vision, such as:
- Eyeglasses
- Contact Lenses
- Surgery on the muscles around the eyes
- Low vision tools (such as magnifying devices)
READ MORE: Low vision aids for reading and daily activities
Keratoconus (corneal thinning)
The cornea (the clear front part of the eye) is approximately 15% thinner in the eyes of people with Down syndrome. One study found that the risk of keratoconus was 30 times higher in people with Down syndrome due to this factor. Keratoconus is a type of anterior segment anomaly affecting the cornea, causing it to bulge.
Keratoconus is normally diagnosed during a person’s teenage years. Symptoms of keratoconus may include:
- Cloudy vision
- Distorted vision
- Light sensitivity
- Poor night vision
- Seeing "halos" when looking at lights
There are a number of ways to treat keratoconus, such as:
- Eyeglasses or contact lenses
- An ultraviolet treatment called corneal cross-linking
- Corneal transplant
- Implanted corneal ring to help flatten the cornea's surface
Brushfield spots in the iris
It has been reported that between 13% to 77% of people with Down syndrome have Brushfield spots in their eyes. Brushfield spots are tiny brown, gray or white spots on the outer edge of the iris (the colored part of the eye) caused by a buildup of connective tissue.
Brushfield spots are more common in those with green, blue or hazel eye colors.
Thankfully, Brushfield spots have no negative impact on the eyesight of a person with Down syndrome.
Cataracts in Down syndrome
The development of cataracts — clouding of the eye's clear natural lens — is another common eye problem in Down syndrome. It is reported to affect between 4% to 72% of people who have the condition, depending on age and other factors.
Children who have Down syndrome are 10 times more likely to have congenital cataracts than those without the condition.
Additionally, some studies have found that adults with Down syndrome may be at a higher risk of developing age-related cataracts earlier in life.
Symptoms of cataracts include:
- Blurry vision
- Double vision
- Colors seem faint or faded
- Seeing halos around lights
- Problematic night vision
Because cataracts can sometimes be hard to detect in babies and small children, the National Down Syndrome Society recommends that children born with Down syndrome have their first eye exam at birth, followed by another exam within six months.
Cataracts are typically treated with surgery when eyeglasses no longer help and the cataract is interfering with daily activities. During cataract surgery, the clouded eye lens is removed and replaced with a new, clear artificial lens called an intraocular lens (IOL), improving eyesight.
Blepharitis (eyelid inflammation)
It is reported that between 10% to 82% of people with Down syndrome develop blepharitis, which is an inflammatory condition affecting the eyelid.
Some researchers attribute the high incidence of blepharitis to common eyelid malformations seen in Down syndrome, such as eye folds (epicanthal folds) and upward slanted eyes (upward palpebral slant), as well as lower immunity.
Generally speaking, most cases of blepharitis are caused by a buildup of bacteria on the eyelid and eyelashes or blocked oil glands.
Symptoms of blepharitis include:
- A gritty or burning feeling in the eyes
- Itchy, red or crusted eyelids
- Dry eyes
- Watery eyes
- Light sensitivity
- Foreign body sensation (a constant feeling of dirt or another irritant in the eye)
In most cases, blepharitis is treated by removing the crust built up on the eyelids and eyelashes and then keeping these areas clean so the condition does not reappear. This can be done through:
- Using warm compresses to break up and remove crust buildup
- Cleaning the eyelids with baby shampoo or an eyelid cleanser
- Massaging the eyelids regularly to keep eyelid gland oil from collecting
- Administering eye drops or medications prescribed by your doctor
READ MORE: Eyelid inflammation: Causes and treatment
Retinal issues
Retinal abnormalities are a significant concern for people with Down syndrome. These issues affecting the retina — the light-sensitive tissue at the back of the eye needed for vision — can lead to various complications.
Retinal issues that may impact a person who has Down syndrome include:
- Retinal detachment – The retina separates from the back of the eye
- Retinal degeneration – The loss of retinal cells over time, impairing vision
- Foveal hypoplasia – The underdevelopment of the retina’s fovea, which is critical for sharp vision
- Macular edema – The irregular collection of fluid in the retina’s macula, causing blurry vision
- Retina blood vessels – Abnormal structure of the eye’s blood vessels
Retinal abnormality symptoms vary depending on the condition. Some of these symptoms may include:
- Vision loss
- Floaters (spots or squiggles in your vision)
- Double vision
- Blurred vision
- Light flashes (photopsia)
- Blind spots
Treatments will vary depending on the underlying retinal disease. Some treatment options include:
- Medicinal injections into the eye
- Laser therapy
- Surgery for certain types of retinal conditions (such as vitrectomy)
Tearing and tear duct abnormalities
It is quite common for people with Down syndrome to have thin or abnormal tear ducts— called nasolacrimal ducts — that frequently become blocked. This can lead to:
- Watery eyes
- Overflowing tears
- Irritated eyelids
- Tear duct system infection (dacryocystitis)
Nasolacrimal duct obstructions (NLDO) — or blocked tear ducts — are usually treated by massaging the area on the side of the nose near the eyes to reopen the ducts. If that does not work, surgery may be required to reopen the tear ducts.
READ MORE: Blocked tear ducts: Causes, symptoms and treatment
Treatment and support options for Down syndrome vision issues
Treatment of eye problems associated with Down syndrome is dependent upon the type of issue, how advanced it is and the current treatments available. Several treatment options are available to address the common eye and vision issues associated with Down syndrome.
For example, some Down syndrome-related eyesight issues can be corrected or addressed with prescription eyeglasses or contact lenses, including:
- Refractive errors
- Strabismus
- Keratoconus
- Nystagmus
Some complications affecting the eyes of people with Down syndrome may require surgery. These conditions include:
- Strabismus
- Keratoconus
- Cataracts
- Tear duct blockage
- Retinal abnormalities
An eye doctor may also prescribe vision therapy for certain eye conditions associated with Down syndrome, especially those involving eye movement or how well the eyes work together.
Types of vision therapy might include:
- Special eye exercises to help visual processing
- Patching
- Prisms to fix eye misalignment
- Orthoptics to improve how well the eyes work together
There are several tools and devices that can help those who have Down syndrome and low vision or visual problems, such as:
- Screen readers
- Voice command apps
- Handheld magnifiers
- Glasses set with magnifiers
- Voice-to-text applications
- Talking calculators
Importance of regular eye exams
Between 60% to 80% of individuals with Down syndrome are reported to have an eye problem. The earlier a doctor can identify any eye or vision issues, the better the outcomes in terms of diagnosis and treatment.
For this reason, it is recommended that children who have Down syndrome receive an eye exam before they reach six months of age, followed by annual eye exams after their first birthday or as recommended by their doctor. It's also suggested that adults with Down syndrome have eye exams at least once per year.
And because most children who have Down syndrome also experience delays in speech development, pediatric eye doctors are specially trained to perform nonverbal eye exams that use visual objects — like toys and picture cards — and hand gestures to communicate.
READ MORE: When to visit a pediatric ophthalmologist
