Babies are not born with perfect vision. It is normal for them to be farsighted with some astigmatism until they are able to see well at about one year old as the brain and visual system mature. In children whose vision does not correct itself spontaneously with growth and maturation, the most common errors are refractive errors. These are caused when the shape of the eye does not correctly focus the light rays entering the eye. They include shortsightedness (myopia), farsightedness (hyperopia) and astigmatism. With myopia, a child can see objects clearly close up, but has trouble seeing further away (like the classroom blackboard). Myopia is most commonly diagnosed in children between the ages of 8 and 12, usually gets worse during the teenage years, but stabilises in early adulthood. If the child is farsighted, words on a page will seem blurry, but distance vision is not as much of a problem. Hyperopia is particularly common in young children, but they may not notice any blurriness because their eyes can compensate by focusing. Astigmatism distorts or blurs vision for both near and far objects. It happens when the cornea is irregularly shaped, and is more like a rugby ball than like a soccer ball. Myopia and hyperopia can be combined with astigmatism, or astigmatism can occur on its own.

Warning signs

Most children should have their first vision assessment at 3 to 4 years of age, but a visit to the optometrist may be advisable earlier if there is a family history of eye problems or if the parents notice certain visual behaviours that seem different from those of other children. If your baby seems to be visually inattentive, is not tracking and following objects by 4 months of age, or recognising you from across the room between 6 and 9 months, there may be cause for concern. Warning signs in older children may include covering one eye, tilting the head, or squinting to see objects more clearly, sitting too close to the TV or holding a book too close while reading, or difficulty concentrating on an activity for long periods of time. Excessive eye rubbing, redness or watering of the eyes after reading or engaging in activities close up, headaches or eye pain may indicate that your child is experiencing eye fatigue or strain.

Comprehensive eye examination

A comprehensive eye examination usually includes an assessment of the clarity and sharpness of vision, the alignment of the eyes and how they function together, depth perception, and the overall health of the inside and outside of the eyes. The optometrist may dilate the pupils with eye drops in order to examine the retina and optic nerve at the back of the eye more effectively.

Correcting vision in children

Optimal learning, either informally through play or in the formal setting of a classroom, is dependent on optimal vision. The most common reasons to prescribe glasses for children are to facilitate normal vision development, to improve vision and help the child to function better in his environment, to help straighten eyes that are crossed or misaligned, to help strengthen a weak or "lazy" eye, and to protect one eye if the child has poor vision in the other. Not all refractive errors need to be corrected, and sometimes the optometrist may decide not to prescribe glasses, to allow the child's natural focusing mechanism to correct the error.

Getting the child to wear glasses

Parents may be overwhelmed when they find out that their child needs glasses, and they may wonder how they will accomplish the seemingly daunting task of getting their child to comply. One expert commented that "generally if a child needs glasses she will wear them because kids like to see their world clearly". While it may be as simple as that for some children, it may be more difficult with others. Another expert says: "It is non-negotiable, like holding an adult's hand to cross the road!"

Children do not have the maturity to understand the possible long-term consequences of not wearing their glasses, and parents need to understand their concerns while still ensuring that they wear their glasses.

Whether or not to wear glasses is not up to the child, but he may accept them more readily if he is included in the process. Discuss with your optometrist the important criteria that need to be taken into account, and allow your child to choose his own frame within these guidelines.

To keep pace with the active lifestyle of children, the frames need to be durable. Plastic frames are less easily bent out of shape and damaged than metal frames. For eye protection, the lenses should be made of a material which will resist impact, so that they are not prone to scratch or shatter. They should offer protection from the damaging UV rays of the sun, and filter out harmful blue light from digital screens. Your optometrist will ensure that the glasses fit correctly and feel comfortable to the child. If possible, an extra pair of glasses may be useful for times when the child forgets to wear them to school. If the child is wearing contact lenses, a pair of glasses is essential to prevent eye strain from over-wear of the lenses.

Common concerns of parents

If my child uses her glasses all the time, she becomes dependent on them. While she may be able to cope without her glasses, your child will appreciate how much better her vision is with her glasses. It is to her benefit to encourage her to depend on her glasses to see clearly without strain.

If my child needs glasses, does this mean that he has "weak eyes?" If the structures of the eyes are healthy, and glasses help him to focus better, your child's eyes are not considered weak.

The glasses should be worn only to see the board at school. The glasses should be worn whenever the child feels she needs them in order to see clearly and function optimally at what she is doing. Talk to your optometrist for guidance.

I passed my astigmatism on to my child. There is a tendency for astigmatism to run in families, but the genetics are not very clear, and sometimes it just happens for no apparent reason.

My child will need to have her eyes examined more often now. People with refractive errors should have a thorough eye examination once a year in order to make any adjustments to their prescriptions and assess their eye health. Unless your child reports problems with her vision before one year or your optometrist recommends an examination sooner, an annual check-up is probably all that is necessary.