All newborn children should have their eyes screened before leaving the hospital. This examination will include an assessment of the general health of the eyes and a red reflex test, which screens for abnormalities at the back of the eye and conditions such as cataracts (clouding of the eye lens). Examination of the newborn can reveal eye problems that are present at birth, many of which are potentially serious threats to the child’s vision.

During the child’s first two years of life, a pediatrician will perform a basic visual examination during the child’s regular well-child visits. Initially, an infant’s vision is quite blurry, but begins to sharpen rapidly after about 6 months of age. Beginning at the age of 3 years, children are tested regularly to examine external functions (e.g., tear ducts, eyelashes), assess visual acuity (distance vision), and to check whether or not the child’s eyes are straight and how well they work together.

Types of vision tests given by a physician, typically an ophthalmologist, include a refraction test (to measure the eyes’ need for corrective lenses), visual field test (to check for gaps in the range of vision) and color vision test (to check the child’s ability to distinguish colors).

Conditions that may be detected in vision tests of children include:

• Lazy eye (amblyopia). This condition is the result of having crossed eyes or having a difference in refractive error (problem with the eye’s ability to bend light) between the two eyes. The test for amblyopia involves determining whether or not the eyes are straight and how well they work together. When caught early – especially by a child’s preschool years – lazy eye can be successfully treated. Left untreated, it can lead to permanent vision loss in the affected eye, as the brain will begin to ignore signals coming from that eye.
  
  
• Cross eyes (strabismus). A misalignment of the eyes that causes them to turn in, out, up or down. Placing a patch over the healthy eye can force the weaker eye to work harder, thereby strengthening it. Surgery or special glasses also are sometimes used to treat this condition.
  
  
• Drooping of the upper eyelid (ptosis). A condition caused by weakness of the muscle responsible for lifting the eyelid, damage to nerves associated with those muscles or looseness of the skin of the upper eyelids. It is often caused by an underlying condition that may be treated or the ptosis itself may be treated with surgery.
  
  
• Refractive problems. These occur when the shape of the eye does not properly bend (refract) light, causing blurring of sight. Examples include nearsightedness (poor distance vision), farsightedness (poor near vision) and astigmatism (imperfect curvature of the eye’s front surface). Refractive problems typically are treated with eye glasses or contact lenses.
  
  
• Color vision problems. A deficiency in seeing certain colors (e.g., shades of red or green). The condition is more common in boys and does not require treatment.
  
  
• Infantile cataracts. Clouding of the eye’s lens that sometimes occurs in newborns. Surgery typically is used to treat this condition.
  
  
• Congenital glaucoma. Rare, inherited form of glaucoma (high eyeball pressure that damages the optic nerve) that appears in newborns. Medications or surgery may be used to treat this condition.
  
  
• Retinoblastoma. Malignant (cancerous) tumor of the eye that usually appears by age 3. Laser surgery, radiation and chemotherapy are all used to treat this condition.
  
  
• Other genetic or metabolic eye diseases. These are conditions that make certain eye problems – such as retinoblastoma or cataracts – more likely. If genetic or metabolic eye diseases are detected, it is likely that the child will be required to undergo more frequent examinations.