Ptosis is a condition which causes your eyelid to droop in one or both eyes. It can cause obstructed vision and can lead to more severe vision problems in children.
You can be born with ptosis or it can develop later in life, following an injury. The condition can be treated with surgery.
Ptosis occurs when the muscle that raises the eyelid doesn't work properly. This causes one or both eyelids to droop. In some cases the droop can be severe enough to limit vision.