A Child’s Eye Exam

Why Worry About a Child’s Eyes?
Children are able to see as soon as they are born.  For the visual system to continue to develop properly, children need clear input from both eyes to the brain.  If there is some problem that interferes with vision in either eye or both, the connections from the eye to the brain can become weak or not develop properly.  Crossed or turned eyes or imbalance in refractive errors can interfere with this normal development of the visual system. 

Because of the importance of normal vision in infants, and because of our abilities to recognize and treat problems early, we are interested in examining very young children.  This is especially true if the parents or the child’s doctor feels that there may be some problems, or if there is a family history of eye problems.

What Questions Are Asked at the Exam?
A child’s eye examination begins by discussing any problems the parents recognize.  It is important to find out if there were problems with the pregnancy or with the child’s birth, and if the child’s growth and development are proceeding normally.  A history of eye problems in the family is important.  We need to know about the child’s health in general.  Are there other medical problems?  Has the child had any treatment with medications or surgical procedures?  Does the child have any allergies?

How Do You Examine A Baby’s Eyes?
Many parents are quite surprised to find that we are able to perform complete eye exams on children.  A skilled ophthalmologist (medical eye doctor) can get a good idea of how well a child can see based on the way a child uses his eyes to fix and follow attractive toys or lights.

No matter how the vision is tested, it is important to check each eye separately.  Two to five percent of children have one eye which does not see as well as the other, a condition called amblyopia or “lazy eye”.

Lights, Lights, and More Lights?
We use lights to examine the pupils to see if the eyes are working properly.  During this portion of the examination, the areas around the eyes, such as the eyelids and the tear canals, are also examined.

The tiny flashlight can be used to see if a child’s eyes are straight or turned.  If a child is looking straight at the flashlight, it will reflect off the front of the child’s eyes in a way that allows us to tell whether the eyes are turned or straight.  This is important in infants because their wide noses may make their straight eyes look crossed.  Sometimes, we cover one eye and then the other.  If the eyes are not aligned properly, they will jump back and forth when looking at the light or a toy.  Wedge-shaped pieces of clear plastic called prisms can be used to measure the amount of misalignment of the eyes.

Why are Eye Drops Needed?
One of the least enjoyable but most essential portions of an eye exam is the dilation of the pupil.  This not only allows us to view the inside of the eye, but the dilating drops temporarily weaken the child’s focusing power so that we can accurately measure for nearsightedness, farsightedness or astigmatism (refractive errors).  Most doctors have preferences for which dilating drops they use.  Some drops are given once, some are given more than once, and all take about 30 to 60 minutes to be fully effective.  It may be necessary to have special drops or ointment put in at home and to return to complete the examination
at a later date.

What Happens After the Drops?
Even though your child may not wish to talk at this point or may even be asleep during the exam, we can determine if your child’s eyes are out of focus, using small lenses and a special flashlight (called a retinoscope).  By shining a beam of light into the eye, we can see the back of the eye reflecting the light and, by holding lenses in the path of this reflection, see whether the child is nearsighted, farsighted, or has astigmatism.  It’s a different technique from that which ophthalmologists use to fit glasses for adults, but it is
nonetheless very accurate.  This tells us if your child needs glasses.

How Do We Check Inside the Eye?
Once your child’s pupils are dilated, your ophthalmologist can get a good look at the inner eye structures to make sure the inside of the eye is healthy.  The inside of the eye holds the retina which functions much as does film in a camera, processing the visual information into signals which are sent down the optic nerve to the brain.  The optic nerve itself, as well as the blood vessels which supply the retina, can be seen in the back of the eye.  Special instruments allow us to see inside the eye in great detail.

What are Common Eye Problems in Childhood?
Four percent of children have ocular problems that can diminish vision in one or both eyes.  The three most common types of problems that occur are strabismus (misaligned eyes), amblyopia (lazy eye), and refractive errors (focusing problems).

What is Strabismus?
Strabismus is a general term referring to eyes which are pointed in different directions.  One eye may drift in or out, up or down.  Crossed eyes are known as esotropia.  Extropia refers to eyes that are turned out.  Strabismus may be present all of the time or intermittently.  Children with strabismus are usually unaware of the problem.  Strabismus interferes with the development of coordinated use of both eyes together.

What is Amblyopia?
Amblyopia, which is sometimes called “lazy eye”, refers to the development of poor vision in one or both eyes.  It occurs in infancy and early childhood during the sensitive period of visual development.  The earlier amblyopia is detected, the easier it is to treat.  Once this early period of visual development has passed, during late childhood, the ability to lose vision to amblyopia is no longer a substantial threat.

Amblyopia can be caused by ocular problems which prevent normal visual development. The most common causes are strabismus and refractive errors, but any ocular disease which prevents a clear image from being formed on the retina, can cause amblyopia.In order to restore vision, not only must the abnormality causing the amblyopia be treated, but also the amblyopia itself.Patching the good eye under supervision of the child’s ophthalmologist forces the brain to develop it with drops or with extra power in the glasses can be used as an alternative to patching, especially in mild forms of amblyopia and in school-age children who will not cooperate with patching therapy.

When Should I Have My Child’s Eyes Checked?
Most pediatricians examine many parts of the eye during a child’s medical examination. However, they may refer a child to an ophthalmologist if there is difficulty in measuring vision, any sign of amblyopia, or if they suspect an abnormality of the eye alignment or structure.  It is recommended that all children have their vision checked by their pediatrician, family physician, or ophthalmologist between three and four years of age, or sooner (around 6 months to 1 year) if there is a family history of problems.Fortunately, we can do a complete eye exam on children of any age.