 The retina scope is a tool we use to actually neutralize a reflex off of that cornea so we see the whole optical system coming through the eye. We can tell if there's farsightedness, nearsightedness, or astigmatism. We can tell how much because we can neutralize that reflex with lenses until we get to the end point. So it's tedious, and some kids respond better than others. Sometimes it's almost impossible, and we have to ask them to come back because they're crying or they just won't even look at anything you want them to.