When the eyes are open and the lid is lower than is normal, this is known as eyelid ptosis. This is quite common and in children it appears around the time of birth (congenital eyelid ptosis).
The problem can be found in the retractor muscle or the nerve that controls it and can affect one or both eyes. In some circumstances other muscles may also be affected.
Treatment of eyelid ptosis is surgical and is undertaken for aesthetic as well as for health reasons. Since in severe cases it can cover the optic axis and impede sight in the young child causing amblyopia.
As a rule, we wait until the age of 2-5 before operating, in order that the face and head of the child has developed and surgery can be precise. Despite this, post-operative results tend not to be perfect.
In general, however, it is preferable to err on the side of caution rather than lift the lid so far that it cannot close properly. This poorly shutting eye (known as hare-eye) leads to the cornea drying up and to infection.