Lazy eye is a confusing disorder. This is because the eye does not always look 'lazy.' It is a disorder between the coordination of the brain and eye and it usually starts in childhood. It causes the body to favor one eye over the other.
Lazy eye is a disorder of the coordination between the eye and the brain, usually Amblyopia is the medical name for it. The problem is one eye does all the work while the other gets weaker and weaker.
Poor blurry vision in an eye that otherwise seems normal is the main symptom. It is caused by poor transmission of the visual image to the brain from eye in childhood. It is a temporary condition in most cases — thank goodness!
By the way it is possible to suffer form this in both eyes. That is very rare. The one eyed ambyopia is more common. About five percent of kids (one in twenty) might suffer from it. Many people are not even aware they ever have it. This is because it is normal to have slightly stronger vision in one eye.
Sometimes this eye looks so lazy it can actually stray. Mainly it causes poor depth perception. This is rare. Having a crossed eye or turned eye is a completely different eye condition. It is called strabismus. However lazy eye and crossed eyes and turned eyes seem to be used all the time to describe both ambyopia and everything else.
The way to determine whether or not your child has this condition is to take him or her in for a special test called a visual acuity test. It is not done with the letter chart we usually associate with determining eye problems.
A large number of kids with lazy eye go unnoticed until they have their eyes examined when they get older. Therefore, comprehensive vision evaluations by a trained and qualified vision professional are the best idea even for pre-school kids. You don't want your child going through school with undiagnosed compromised vision! Yet it can so easily happen.
Treatment options for lazy eye include glasses, drops, and certain vision therapies, possibly including the use of a patch. Sure you're kid will look like a pirate but at least he will be able to see the chalkboard. Good thing Pirates of the Caribbean was such a hit and pirates are so cool. However expect little girls to have a harder time with corrective eye patch than boys.
You also need to catch this early. Recent research has shown it can be treated until the kid is seventeen. Improvements are possible at any age but the best chance of correcting completely is catching the lazy eye while your child is still a kid.