Squint is an eye condition where the eyes do not look in the same direction. This means that one eye may not focus on an object someone is looking at. While one eye looks forwards to focus on an object, the other eye turns either inwards, outwards, upwards, or downwards. Most squints occur in young children. Sometimes, when a child has a squint, the sight in the eye which turns may be weaker. Squints are common and affect about one in 20 children. You might even spot that your baby has a squint. Most squints develop before preschool age, usually by the time a child is three years old.
Causes of childhood squint
This occurs when there is a problem with the focusing power of the eye. They are usually corrected by glasses. The most common types of refractive errors are:
• Myopia (short-sightedness): causes things up close to be clear, and those in the distance to be out of focus and blurry.
• Hypermetropia (long-sightedness): may cause things both up close and in the distance to be blurry. Hypermetropia also causes the eye to work harder to see things close up.
• Astigmatism: causes blurry vision up close and in the distance, and is caused by the front of the eye not being quite spherical (rounded).
Some squints run in families, so if a parent has had a squint or needed glasses from an early age, there may be an increased chance that their child may also be affected.
Other eye conditions, such as cataract or damage to the retina, can cause the eye to have poor vision. This may also cause a squint to develop in this eye.
Children that are born early (before 32 weeks) may be at more risk of developing a squint.
Children with conditions such as cerebral palsy and Down’s syndrome may also be more prone to develop a squint.
What problems can be caused by a squint in a child?
Amblyopia is sometimes called a ‘lazy’ eye. It is a condition where the vision in an eye is poor, and it is caused by lack of use of the eye in early childhood. The visual loss from amblyopia cannot be corrected by wearing glasses. However, it is usually treatable. If amblyopia is not treated before the age of about 7-8 years, the visual impairment usually remains permanent.
A squint can be a cosmetic problem. Many older children and adults who did not have their squint treated as a child have reduced self-esteem because of the way their squint looks to other people.
Impaired binocular vision
With normal eyes, both eyes look and focus on the same spot. This is called binocular vision (bi- means two and ocular means related to the eye). The brain combines the signals from the two eyes to form a three-dimensional image. If you have a squint, the two eyes focus on different spots, and your child is unlikely to have normal grade of stereopsis (depth perception).
What are the treatments for squint?
Treatment typically involves the following:
• Treating amblyopia (visual loss), if this is present.
• Wearing glasses to correct any refractive error, if this is present.
• Surgery is often needed to correct the appearance of the squint itself and may help to restore binocular vision in some cases.
What is the outlook?
For ‘lazy’ eye (amblyopia), if it develops:
As a rule, the younger the child is treated, the quicker the improvement in vision is likely to be, and better the chance of restoring full normal vision. If treatment is started before the age of about seven years, then it is often possible to restore normal vision. If treatment is started in older children, then some improvement in vision may still occur, but full normal vision is unlikely to be ever achieved.
For improving the appearance of the eyes:
Squint (strabismus) surgery usually greatly improves the straightness of the eyes. Sometimes, even after an operation, the eyes are not perfectly straight. In some cases, two or more operations are needed to correct the squint. It is possible that several years after successful surgery, the squint may gradually return again. A further operation is an option to re-straighten the eyes.
Most children with squints have good level of vision and both eyes working together once they have had treatment. So, it is always necessary to have periodic checkups with the eye specialist, especially the pediatric ophthalmologist.