If I have a lazy eye can I become blind if I dont wear glasses? I have been told the brain gets used to not using it and therefore will get worse.

Define "blind" Think of your eyes as 2 video cameras sitting close together.If they are both focused the same and provide the brain a clear image, the brain is happy. If one is weak, points a different way or otherwise gives a poor image, the brain is mad & can eventually turn of the input.It takes years for this to happen, but it can and does.If you ignore treatment, expect to be functionally blind in one eye.
Amblyopia develops . in childhood when brain " turns off" the visual input from one eye because of misaligned eyes, a high degree of nearsightedness, farsightedness or astigmatism, or visual deprivation from a cataract, droopy lid, etc., The degree of vision loss is ^er than expected from physical problems in the eye. Wear your glasses & protect the other eye from injury. See: www.aapos.org/terms/conditions/21.