Strabismus (squint)

Glasses or contact lenses are used when an uncorrected refractive error is the underlying cause of strabismus. Corrective lenses can help the eyes focus, for example, when there is longsightedness.

Sometimes, special lenses called prism lenses are used. These have a wedge shape that bends light into the eye, reducing how much the eye has to turn to see clearly. These lenses can help people with double vision.

An eye patch can be used when someone has a lazy eye as well as a squint. This helps improve vision in the weaker eye, which can help reduce misalignment of the eyes.

Eye exercises can be prescribed for some types of strabismus to work on the eye muscles controlling eye movement.

Exercises can be helpful for people with 'convergence insufficiency’ when their eyes don't work together when doing close up work such as reading or using a screen.

An injection of botulinum toxin into the eye muscles can treat some types of strabismus as an alternative to surgery. The injection happens under local anaesthetic. This treatment is more common for adults than children.

Eye muscle surgery is a common treatment and can improve the eyes' appearance and restore or improve depth perception (known as binocular vision).

Strabismus surgery changes the position or length of eye muscles to align the eyes. The surgeon will detach and move one or more eye muscle into a new position to allow the eyes to point in the same direction.

The surgery is usually done under general anaesthetic, and most people can go home on the same day. There will be some eye pain for a few days afterwards. Over the counter painkillers can help until this improves. You or your child may also have red and itchy eyes and double vision while recovering.

Your eye doctor should tell you what activities are safe and what to avoid during recovery, and for how long. Adult patients are advised not to drive while recovering from a general anaesthetic and while there is any double vision.

Strabismus in adults can be treated with specialist prism lenses, eye exercises, and strabismus surgery. Adults whose strabismus started in adulthood may struggle with double vision more than people who've had strabismus since childhood.

Treatment can improve symptoms, including double vision and poor depth perception. Surgery can also help improve the appearance of the eyes, helping people who feel self-conscious about how they look with a squint.

One of the more common types of strabismus, this inward turning squint happens due to uncorrected longsightedness. Symptoms include double vision, closing or covering an eye for close up tasks, and head tilt.

This is also a fairly common type of strabismus when one eye can focus on something but the other looks outwards. Symptoms can include headaches, eye strain and closing an eye for distance tasks.

If you develop possible symptoms of strabismus or suspect your baby or child may have a squint, see your health visitor, GP or optician.

An optician will do a detailed eye exam to diagnose strabismus. They can adapt this for very young children. During your appointment, they will:

• Ask about you or your child's health and any history of eye conditions in the family.
• Do a test of visual acuity. For adults, this is the eye chart test you're probably familiar with. Don't worry if your child can't yet speak or understand this type of eye test. Opticians have other ways to assess the vision of very young children or people who can't follow a visual acuity eye test.
• Check for refractive errors such as nearsightedness and longsightedness.
• Look closely at how the eyes move and focus.
• Sometimes they will use eye drops to dilate the pupils for a detailed look inside the eye to assess eye health.

Around 30% of people with strabismus have a family member who has also been affected. If you suspect your child has a squint, you must mention any family history of the eye condition to your GP or optician. Strabismus isn't always inherited, though, with many different causes, including medical conditions and injuries.

Strabismus is not something that children grow out of and can get worse without treatment. An uncorrected squint can also lead to other vision problems, such as a lazy eye (amblyopia).