Frequently Asked Question
Q. What is a squint?
Answer. A squint is a condition where your eyes look in different directions. One eye turns inwards, outwards, upwards or downwards while the other eye looks forwards. The medical name for a squint is strabismus.
The misalignment of the eyes can be caused by a problem with the eye muscles or by
an uncorrected vision problem, such as short-
(( Squints may be constant (apparent at all times) or intermittent (only apparent at certain times). The majority of squints appear in the first three years of life, but some may develop later )) .
Q. How does a squint affect vision?
Answer. In young children, a squint can cause:
•lazy eye (amblyopia)
If your child has a squint, their eyes are no longer working together and they may see two images (double vision) instead of one. To avoid double vision, your child’s brain ignores the signals from the eye with the squint and only recognises images from the normal eye. As the squinting eye is not being used, it eventually becomes ‘lazy’.
In older children, a squint may cause double vision but not result in a lazy eye. This is because their vision has fully developed and their brain is unable to ignore signals from the eye with the squint.
If the vision in the eye that squints is poor, your child may have to wear a patch over their other eye to encourage the vision to develop.
Q. What are the causes of squint?
Answer. Six different muscles surround the eyes and work "as a team" so that both eyes can focus on the same object.
In someone with strabismus, these muscles do not work together. As a result, one eye looks at one object, while the other eye turns in a different direction and is focused on another object.
When this occurs, two different images are sent to the brain -
If the strabismus is not treated, the eye that the brain ignores will never see well. This loss of vision is called amblyopia. Another name for amblyopia is "lazy eye." Sometimes amblyopia is present first, and it causes strabismus.
In most children with strabismus, the cause is unknown. In more than half of these cases, the problem is present at or shortly after birth (congenital strabismus).
Most of the time, the problem has to do with muscle control, and not with muscle strength.
Less often, problems with one of the nerves or muscles, or Graves' disease restriction may cause strabismus.
Other disorders associated with strabismus include:
•Brain and nerve disorders, such as traumatic brain injury, stroke, cerebral palsy,
•Diabetes (causes a condition known as acquired paralytic strabismus)
•Damage to the retina in children who are born premature
•Hemangioma near the eye during infancy
•Injuries to the eye
•Tumor in the brain or eye
•Vision loss from any eye disease or injury
A family history of strabismus is a risk factor. Farsightedness may be a contributing factor, especially in children. Any other disease that causes vision loss may also cause strabismus.
Q. What are Types of squint?
Answer. There are four different types of squint depending on the direction in which the eye turns. They are:
Hypertropia and hypotropia are less common than esotropia and exotropia.
Squints can also be:
•apparent at all times (constant), or
•only apparent at certain times (intermittent).
The cause, severity and direction of a squint will vary from person to person.
Q. What are the Symptoms of squint?
Answer. Symptoms of strabismus may be present all the time, or only when you are tired or sick.
The eyes do not move together and may appear crossed at times.
The other eye will appear turned out, up, or down from wherever the first eye is focused.
Someone with strabismus may also have:
•Depth perception loss
•Abnormal head position
Q. How can squint be treated?
Answer. The first step in treating strabismus is to prescribe glasses, if needed.
Amblyopia or lazy eye must be treated first. A patch is placed over the better eye. This forces the weaker eye to work harder.
Your child may not like wearing a patch or eyeglasses. A patch forces the child to see through the weaker eye at first. However, it is very important to use the patch or eyeglasses as directed.
If the eyes still do not move correctly, eye muscle surgery may be needed. Different muscles in the eye will be made stronger or weaker.
Eye muscle repair surgery does not fix the poor vision of a lazy eye. A child may have to wear glasses after surgery. In general, the younger a child is when the surgery is done, the better the result.
Adults with mild strabismus that comes and goes may do well with glasses and eye muscle exercises to help keep the eyes straight. More severe forms of adult strabismus will need surgery to straighten the eyes. If strabismus has occurred because of vision loss, the vision loss will need to be corrected before strabismus surgery can be successful.
Q. What is the aim of surgery?
Answer. The aim of surgery is :
– To improve the alignment of the eyes in order to make the squint smaller in size and less obvious.
– In some patients, to reduce or try to eliminate double vision or to improve depth
Q. How is the surgery done?
Answer. Squint surgery is a very common eye operation. It usually involves tightening or moving one or more of the outside eye muscles which move the eye. These muscles are attached quite close to the front of the eye under the conjunctiva, the clear surface layer. The eye is never taken out of the socket during squint surgery. Stitches are used to attach the muscles in their new positions. These stitches are usually soluble.
Squint surgery is nearly always a day-
The operation is usually carried out under general anaesthetic. The operation usually
takes up 30-
Q. Does the surgery cure the squint?
Answer. Overall, about 90% of patients find some improvement in their squint after surgery. The amount of correction that is right for one child might be too much or too little for another with exactly the same size squint, so the squint might not be completely corrected by the operation.
Although your child’s eyes could be straight just after surgery, many children require more than one operation in their lifetime. If the squint returns, it might ‘drift’ in either the same or opposite direction. We can’t predict when that drift might occur.
Q. Does the surgery cure the need for glasses or a lazy eye?
Answer. No, the operation does not aim to change the vision or the need for glasses or patching.
Sometimes, more patching is needed after the operation.
Q. What are the risks of the operation?
Answer. Squint surgery is generally a safe procedure. However, as with any operation, complications can occur. Generally, these are relatively minor but on rare occasions they could be serious.
* Under and overcorrection
As the results of squint surgery are not completely predictable, the original squint might still be present (undercorrection) or the squint direction could change (overcorrection). Occasionally, a different type of squint might occur. These problems could require another operation.
* Double vision
Your child might experience double vision after surgery, as the brain adjusts to the new position of the eyes. This is normal and often settles in days or weeks. Some might continue to experience double vision when they look to the side. Rarely, the double vision can be permanent in which case further treatment might be needed.
Squint surgery in children – information for parents
Some patients might have a mild allergic reaction to the medication they have been prescribed after surgery. This results in itching/irritation and some redness and puffiness of the eyelids. It usually settles very quickly when the drops are stopped.
Children might develop an infection or abscess around the stitches. This is more likely to occur if they go swimming within the first four weeks after surgery.
A cyst can develop over the site of the stitches, which occasionally needs further surgery to remove it.
The redness in your child’s eye can take as long as three months to go away. Occasionally, the eye does not completely return to its normal colour, particularly with repeated operations.
Most of the scarring of the conjunctiva (skin of the eye) is not noticeable by three months, but occasionally visible scars will remain, especially with repeat operations. It is important to use any drops or ointment prescribed after the operation to reduce the chance of scarring.
Infection is a risk with any operation and, although rare, can result in loss of the eye or vision.
After the operation
After your child’s operation, their eye(s) will be swollen, red and sore and their vision may be blurred. Start the drops that evening, and use painkillers suitable for children, such as paracetamol and ibuprofen, as required. The pain usually wears off within a few days. The redness and mild discomfort can last for up to three months, particularly with repeat squint operations.
Your child might need a few days or one week off school or nursery. Normal activity
including sports (apart from swimming) can be resumed as soon as your child feels
comfortable to take part. You should return for follow-
Summary of care after the operation:
Use the eye drops and/ or ointment prescribed
Use painkillers such as paracetamol and ibuprofen if your child’s eyes are painful
Use cooled boiled water and a clean tissue or cotton wool to clean any stickiness
from the eyes
Don’t rub the eye(s) as this could loosen the stitches
Don’t swim for four to six weeks
Attend your child’s post-
Continue using glasses if your child has them
Complaint of headache
Has abnormal head position
Q. When to Contact a Medical Professional
Answer. Strabismus requires prompt medical evaluation. Call for an appointment with your health care provider or eye doctor if your child:
•Appears to be cross-
•Complains of double vision
•Has difficulty seeing
Note: Learning difficulties or problems at school can sometimes be due to a child's inability to see the blackboard or reading material.
A service of the U.S. National Library of Medicine
National Institutes of Health