Amblyopia, also known as lazy eye, is an eye condition caused by underdeveloped pathways between the eye and the brain. Amblyopia usually only affects one eye, but can occasionally affect both eyes. Most of the time, the eye has a normal structural anatomy but a defective pathway; the brain ignores the images from the lazy eyes. If amblyopia is detected early in life, it can be corrected. However, if amblyopia is treated too late, the brain will become accustomed to ignoring visual inputs from the eyes leading to decreased vision in the lazy eye.