What to Expect the Toddler Years (164 page)

Keep in mind that a toddler will not be expected to achieve a perfect 20/20 score on an eye exam. The average two-year-old generally scores about 20/60. Vision continues to improve over the next few years to 20/40, but doesn’t reach 20/20 until about age ten.

Protection from the sun.
Long-term exposure of the eyes to the sun appears to increase the risk of cataracts later in life. So get your toddler used to wearing sunglasses or a wide-brimmed hat when outdoors (playing, walking, or riding in the stroller) in strong midday sun for
more than a few minutes. Whether children should always wear sunglasses in the sun is controversial; some experts question whether the eye’s own sun-protective mechanism will develop properly without some exposure to sun.

When buying sunglasses, look for UV-blocking lenses; they block 99% of both UVA and UVB light. ANSI (American National Standards Institute) ratings on sunglass labels provide a good guide:
general purpose
—medium-to-dark tinted lenses for use in any outdoor activity;
special purpose
—for extra-bright environments (in the snow, at the beach);
cosmetic
—lightly tinted for use around town. Side shields and goggles provide extra protection in extremely bright situations (high-elevation snow fields and tropical beaches, for example). To be most effective, they should screen out 75% to 85% of available light (look for this information on the label). Before purchasing sunglasses, be sure to check the lenses for distortions. (Hold the glasses at arm’s length and look through them at a straight line, such as the edge of a door or window, several feet away. Slowly move the lens across the line; if the straight edge becomes distorted, sways, curves, or otherwise seems to move, optical quality is poor.) Tint should be uniform throughout both lenses. Frames should be sturdy and free of rough spots, large enough to block out some side light, and should fit comfortably and stay in place. Coated plastic lenses are the most durable and thus the most practical for toddler use. Gray lenses distort color the least; green or brown are next best. Avoid very dark lenses, which could interfere with a toddler’s ability to see what’s ahead. Keep the glasses from sliding off during play by attaching them with a special children’s headband designed for the purpose.

Protection from injury.
Whenever there’s a risk of eye injury, protective glasses should be worn. The best protective glasses have 3-mm thick polycarbonate lenses and have frames that are approved for industrial or sports use. Leak-proof goggles are a good investment for toddlers who spend a lot of time in chlorinated swimming pools. Keep in mind, underwater swimming is not recommended.

Though parents have been telling kids otherwise for generations, it’s not true that reading or playing in dim light can damage vision. But because not having enough “light on the subject” can cause temporary eye strain and headache, always provide your toddler with adequate lighting.

The major injury risk to a toddler’s eyes is from an accident at home, at day care, or at the playground. So be sure to follow the safety recommendations in Chapter Twenty-one. Take particular care to: Keep your child from playing with toys that have sharp points or rods, with sticks, or with pencils and pens, except under close supervision (never allow these items in a moving car); cushion sharp corners on furniture (especially tables that are eye-level for your toddler); teach your toddler never to run with toys in hand; keep all toxic substances out of your toddler’s reach (many can do eye damage on contact; see page 637); keep your child away when you are mowing the lawn or operating a snow blower (see page 646); use safety guards on power equipment. For information on home eye safety, contact the Prevent Blindness America Society (see page 482 for their website).

Protection from television.
While no amount of TV will permanently damage a child’s eyes, prolonged viewing can induce temporary eye strain. Minimize the risk by limiting television (see page 159); when the TV is on, keep the room adequately lighted, adjust the lighting to minimize glare from the screen, and insist that your toddler take viewing breaks every half hour. Also make sure your child doesn’t sit too close to the set (the most
desirable distance is at least five times the width of the screen); a child who repeatedly gravitates back closer to the screen may be nearsighted, and should be tested. (The American Academy of Pediatrics recommends that children under the age of two not watch television at all.)

Protection from allergens.
A child who is prone to runny eyes during allergy season should wear wraparound glasses or goggles as often as possible when outdoors to keep pollen and other irritants out. Air-conditioning and air filters can help reduce irritation indoors. Summering in a cool climate, when feasible, is also helpful.

For information on treating eye injuries, see page 669; on eye infections, see page 842.

Vision problems often go undiagnosed in toddlers because they are too young to complain. Recognizing the warning signs on page 478, should they show up in your toddler, and reporting them to the doctor will allow for prompt diagnosis and treatment, which may help to prevent a condition from getting worse as well as head off related problems (such as learning difficulties, low self-esteem, and so on) that can develop in children when they can’t see well.

The eye problems most common to toddlers are:

Blinking.
What is it?
Repetitive opening and shutting of the eyes.
Who is susceptible?
Any toddler.
Signs and symptoms:
Generally, just the blinking, though if lack of sleep is the cause, there may also be eye-rubbing.
Causes:
In some toddlers, repetitive blinking is simply a habit that is picked up when they notice that quickly flicking the eyelids makes for an interesting visual perspective; in others, it’s a copy-cat habit, picked up from peers; in still others, it’s a result of inadequate sleep (but there will usually be other signs, too, such as crankiness) or of stress overload (though this reaction is much more likely in an older child than a toddler). Very, very rarely, blinking is a manifestation of a petit mal seizure disorder.
Treatment:
When not accompanied by other symptoms, repetitive blinking is generally benign and self-limiting; in most cases, it stops on its own within anywhere from a week to several months. If the blinking seems to be stress-related, reducing the stress in your child’s life (see page 173) can often bring the behavior to an end. No matter what the cause, nagging your child about blinking is only likely to make the habit persist. If blinking is accompanied by any of the symptoms on page 478, is virtually nonstop, or seems to bother your child, check with the doctor.

Nearsightedness
(myopia).
What is it?
An inability to see clearly objects more than a short distance away.
Who is susceptible?
Most often, children who have a nearsighted parent or parents. Though some children become nearsighted in the second or third year of life, the condition more often develops later.
Signs and symptoms:
Squinting, holding books and other objects very close, sitting close to the TV, difficulty identifying distant objects.
Causes:
Most often, an eyeball that is elongated rather than sphere-shaped, causing the image of distant objects to fall short of the retina at the back of the eye and thus to appear blurred. Occasionally, the cornea or lens is responsible for the distortion. Genetics is definitely a factor in the development of myopia; but there may be others that are as yet unknown.

Treatment:
Eyeglasses or contact lenses can correct the visual deficit; because of rapid eye growth in young children, prescriptions may have to be checked (and changed) every six months or so. Clinical trials are presently underway to determine the long-term safety and effectiveness in children of radial keratotomy, a surgery that reshapes the curve of the cornea to correct myopia.

Farsightedness
(hyperopia).
What is it?
An inability to see clearly objects that are close.
Who is susceptible?
All babies and young children tend to be somewhat farsighted, but in most the vision normalizes eventually. Those who remain farsighted usually have a family history of farsightedness.
Signs and symptoms:
Backing away from close objects, as though trying to see them better; disinterest in close work: looking at books, doing puzzles, stringing beads, or playing with toys that require close vision; eye-rubbing; strabismus (cross-eyes).
Causes:
Most often, a flattened eyeball, which shortens the distance to the retina, causing the observed image to fall behind it and thus to appear blurred. Occasionally, a weakness of the cornea or lens is responsible for farsightedness.
Treatment:
Corrective lenses are considered necessary only when farsightedness is extreme, and interferes with play and other activities, and/or causes discomfort or mild headaches.

Astigmatism.
What is it?
Vision that is blurred or wavy; objects look the way they might look when reflected in a fun-house mirror.
Who is susceptible?
Anyone, but children who are either nearsighted or farsighted are the most vulnerable to astigmatism, which is usually present at birth.
Signs and symptoms:
Squinting, holding books and objects close to the face, sitting close to the TV, headaches, eyestrain. The symptoms are similar to those of farsightedness, but the conditons can be differentiated through medical evaluation.
Causes:
An uneven curvature of the cornea and/or the lens of the eye.
Treatment:
Eyeglasses or contact lenses can usually correct an astigmatism; eyeglasses are safer for toddlers, unless the condition is severe enough to warrant the use of contacts, which are more effective in reshaping the eye, or surgery.