Children's Services

Lazy eye (amblyopia)

Amblyopia, more commonly known as ‘lazy eye’, affects around 4% of the general population and means one eye has less vision than the other.

Lazy eye in children doesn’t typically cause any symptoms, although it may be associated with a squint in some cases. It is usually detected during a school vision screening or following a routine visit to the optician.

Other conditions can sometimes be referred to as ‘lazy eye’ as well. These include:

  • Squint
  • Misalignment of the eyes known as strabismus
  • Droopy eyelid known as ptosis

It is important to differentiate between these conditions, so that the appropriate advice is given. The information on this page is exclusively about amblyopia.

Causes of lazy eye

Difference in the power of the two eyes

If the refractive power of each eye is significantly different, so if one eye has a high minus or plus power, the brain chooses to use the other eye to see. This results in under development of the eye with the high error.

Squint or Strabismus

Some children may be born with or develop a squint, which leads to the eyes being misaligned. As a result, when one eye looks straight ahead the other may be turned in or outwards. If this is a constant phenomenon it leads to poor vision in the deviating eye.

Stimulus deprivation

This occurs when the vision of one, or both, eyes is impaired temporarily by a cataract, or a droopy eyelid in childhood. This leads to an unequal signal to the brain from the two eyes and as a result the eye with the worse vision under develops, even when the deprivation is removed.

Lazy eye treatment

If your child is found to have amblyopia it is important that treatment begins as soon as possible. Lazy eye treatment for children tends to work best if it begins before the age of seven. However, if the condition is picked up a little later, there are still things we can do to help.

The principle behind treating amblyopia in children is penalising the good eye, to encourage the eye with the poorer vision to develop further. There are a few options for approaching this. Mr Saurabh Jain can advise on the best approach to take, and we will monitor how the treatment is working. These are the options for lazy eye treatment for kids:

Patching of the good eye

This lazy eye treatment simply involves wearing a patch on the good eye, so that the lazy eye has to do all the work. This can be carried out between 30 minutes to six hours a day, depending on the severity of the amblyopia. Recent reports suggest that a maximum patching time of two hours is sufficient for most moderate cases.


In children unable, or unwilling to wear an eye patch for lazy eye, drops can be used to blur the vision on the good eye on a semi-permanent basis. This has the advantage of avoiding a patch and has been shown to be as good as patching in most cases.

Squint surgery

For the best results, surgery in patients with amblyopia should be carried out once the treatment is complete and no further improvement in vision is expected.