A young boy getting an eye patch placed over his right eye.

We’re funding research to help understand lazy eye (amblyopia), because we believe that people’s sight matters.

Lazy eye, medically known as amblyopia, is a condition where vision in one eye (or rarely both eyes) does not develop properly during childhood. This occurs when the brain favours one eye over the other, eventually ignoring signals from the weaker or lazy” eye.

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Up to 4%

of children are affected by lazy eye

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Around 20%

of children will develop a recurrence of lazy eye after completion of treatment

Causes of lazy eye

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Lazy eye typically develops in early childhood, usually before age 7, when vision is still developing. Early diagnosis and treatment are crucial for preventing long-term vision problems.

The cause of lazy eye can depend on the type of amblyopia:

  • Strabismic amblyopia: (also known as squint): This is the most common type of amblyopia, where an imbalance in the eye muscles prevents the eyes from working together properly, causing one eye to cross in or turn out. This causes the eyes to look in different directions to each other. The brain will ignore input from the misaligned eye to avoid double vision. 
  • Refractive amblyopia: this is caused by differences in prescription between the eyes, for example one eye may have farsightedness, nearsightedness, or astigmatism, while the other does not. This can cause the brain to ignore signals from the weaker eye.
  • Deprivation amblyopia: this is where vision is obstructed in one eye which can lead to amblyopia. This can be caused by cataracts, droopy eyelids (ptosis), or corneal scars

Risk factors such as a family history of amblyopia, premature birth and small size at birth, and developmental disabilities can be associated with an increased risk of lazy eye.

Symptoms and treatments

Lazy eye is often first diagnosed during an eye test. Signs and symptoms in children can include:

  • Shutting one eye or squinting when looking at things
  • Eyes looking in different directions to each other (this is known as strabismus or squint)
  • Tilting their head when looking at something
  • Experiencing headaches, having tired eyes or rubbing their eyes a lot. 
  • Poor depth perception, which can cause children to trip or fall over a lot, and have difficulty catching or throwing. 

However, many children do not notice anything wrong with their vision, and lazy eye may not be evident without an eye test, so it is important for children to have their eyes tested regularly. 

Treatments for lazy eye

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Treatment options for lazy eye will depend on what’s causing it.

The aim of treatment will be to improve vision in the weaker eye. 

Treatments can include:

  • wearing glasses to correct vision
  • covering the stronger eye with an eye patch for a few hours a day, which will help to stimulate the brain to use the weaker eye
  • applying eye drops to temporarily blur the vision in the stronger eye, which can help the development of better vision in the weaker eye 
  • if lazy eye is caused by cataracts or a drooping eyelid, surgery may be required
  • surgery may also be required to correct a squint – this will straighten the eyes and allow them to work together better, but does not improve vision.

Treatment should ideally start before the age of 7, when vision is still developing.

After treatment, children need to be monitored for recurrence of lazy eye as they will need to start treatment again if lazy eye reoccurs. 

Investing in lazy eye

We supported research which demonstrated that children can test their own vision using child friendly tests, independently and with repeatable results.

This is especially relevant for children undergoing lazy eye treatment, who may have to have their vision checked every 8 – 12 weeks.

We’re also funding other research on lazy eye. You can read about some of our most recently funded projects below.

Recent progress