All you need to know about eye squinting.
A squint occurs when one eye is straight and the other eye turns away form the straight position. The improper aligning of the eyes affects depth of perception, and can result in poor vision and head positioning.
This condition can happen at any age. The squinting eye can turn inwards (convergent squint) or outwards (divergent squint). A squint can also be vertical with one eye higher than the other. Squints can be constant, present all the time, they can be intermittent and occur in certain situations, like when the child is reading, tired or when he is looking in the distance.
When a squint is constant, three things can occur:
Amblyopia or “lazy eye”
- When a child has a constant squint, he does not use the squinting eye to see and this will result in that eye having poor vision. An eye that has poor vision from lack of use is said to be lazy or amblyopic.
Poor binocular vision
- The ability to appreciate depth or stereovision requires both eyes to be aligned so that they can be used as a pair. A child with a constant squint has no binocular or stereovision.
Abnormal head position
- Some children adopt an abnormal head position like a tilt or face turn when they have a squint to try to keep both eyes aligned.
Squints are often congenital in nature, meaning that some are born with the condition. In certain cases, the condition develops during infancy. Some squints can also be caused by:
- Uncorrected long-sightedness (hyperopia)
- Uncorrected short-sightedness (myopia)
Glasses can sometimes reduce or completely eliminate the squint and the need for surgery. All children with squints should have their eyes checked and glasses, if prescribed, should be worn at all times to help straighten the eyes. If the glasses do not completely eliminate the squint, surgery is then needed for the remaining squint.
When to seek help
Preferably when the condition at an early age, it is recommended for the child to undergo treatment as soon as possible.
- A child with untreated amblyopia will always have defective vision.
- A child with a constant squint will have no binocular vision. Early amblyopia treatment and/or squint operation may be required to enable the squinting child to have good vision in both eyes with normal binocular function.
Treatment of a child with a squint consists of two parts:
Existing amblyopia must be treated first.
- This can be done by patching the good eye, forcing the child to use the lazy eye. When the vision in the squinting eye becomes normal, the child will use each eye equally and the squint will be noted to alternate between the eyes.
- Once vision is restored in the amblyopic eye, squint surgery is performed to realign the eyes and to allow binocular vision to develop. Binocular vision can only be regained when a child is young.
When surgery should be done:
- In a young child with a constant squint, surgery should be done once vision is equal in both eyes to enable binocular vision to develop.
- In a child with intermittent squint, surgery is not so urgent as he experiences binocular vision some of the time.
- In an adult, if squint has been present for a long time and binocular vision is not possible, surgery can be done to improve his appearance.
Where to seek treatment
The medical institutions within SingHealth that offer consultation and treatment for this condition include: