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What are the screening tests?

  • Look at a letter chart.
  • Look at a book through 3D glasses to check stereoscopic vision.
  • Look at a camera three feet away. The camera takes a picture of the eyes that shows how well they focus.

These tests are presented as games and usually take about 15 minutes. There is no conceivable risk. Public Health will send a letter with the results either by mail or with the child.

If I'm told that my child should see an optometrist, does that mean something is wrong?

Not necessarily. The odds of a problem are roughly 50:50.

Our family doctor sees nothing wrong with my child's eyes yet the screening test does. Why?

Eye problems are rarely obvious in young children. Testing eyes properly requires specialized training and equipment that family doctors lack.

If the screening tests found nothing wrong with my child's eyes, does that mean everything is okay?

Probably but not certainly. The odds are roughly one in 15 that the screening tests missed a problem. To be sure you need to take your child to an optometrist for a complete eye exam. For children, OHIP will cover the cost of one optometric exam every 365 days.

What does an eye exam entail?

The optometrist has your child look into various machines and she peers into the child's eyes with a light. Since it is hard to see inside a child's eye, the light is bright and the doctor uses eye drops to enlarge the pupil. None of this is painful, although the light and drops may be uncomfortable. A complete exam takes about an hour, including time spent waiting for the drops to take effect.

Are the eye drops necessary? Are they dangerous?

The eye drops are necessary to diagnose far-sightedness, which is much the most common eye problem among kindergarteners. They are not dangerous. Nobody enjoys them but they are essential and routine.

What are the most common eye problems in kindergartens?

  1. Far-sightedness (hyperopia) is the ability to focus only at a distance. This is hard to spot because it doesn't affect a kindergartener's play, but it worsens reading-readiness. Far-sightedness also leaves the eye in danger of going crooked, which risks amblyopia (problem #3).
  2. Astigmatism blurs lines at some angles but not at others, leaving most things unclear. Here is an example.

         example of astigmatism
  3. Risks of amblyopia. If the two eyes cannot work together, and if this is not corrected by age eight, then the brain will give up trying to use one eye, leaving it blind. (The eyes captures optical information but we see that information with the brain.) This can happen if the eyes are imperfectly aligned—i.e., if one eye looks inward or outward—or if one eye is weaker than the other (anisometropia).
  4. Near-sightedness (myopia) is the ability to focus only close up. Near-sighted children have trouble seeing the blackboard.

If my child needs glasses, how bad is his vision?

Adjust the size of the image below (or move in and out) so that you can read the top line but only just. Now the second line shows how a far-sighted child might see the letters in a book or how a near-sighted child might see writing on the blackboard. The third line shows how an astigmatic child might see both.


This illustrates the vision of children who need only modest correction. Your child may see worse than this.

Why does my child need glasses? Nobody else in my family has needed them.

For perfect vision every part of each eye must always grow at exactly the same rate. This does not always happen. Just as different parts of the body can grow at different rates, so can different parts of the eye.

Growth is affected by genes and the environment. The key environmental factor affecting the eye's growth and need for glasses seems to be the amount of sunlight a child experiences while growing up—i.e., the amount of time the child spends out of doors.

Why not give my child a few years to see if he or she grows out of the problem?

Because, depending upon the problem, either his schoolwork may never recover or he may lose the use of an eye.

Can't glasses weaken the eyes?

No. Here's a sensible discussion of this by the BBC.

What about exercises?

Some eye problems involve weaknesses that exercises can fix. Those are muscular or neurological weaknesses, and an optometrist will prescribe exercises for them when appropriate. However, most people need glasses because the shape of the eye is imperfect. No form of exercise can reshape the eye.

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