The key to amblyopia treatment is early detection and early treatment, which is usually better before the age of 8 and worse after the age of 12. During the critical period of visual development (from birth to 3 years old) and the sensitive period (before 12 years old), children are prone to damage of visual function such as strabismus, monocular form deprivation, refractive aberration and high refractive error (myopia, hyperopia, astigmatism), resulting in amblyopia. Amblyopia treatment is a combination of refractive correction (i.e., wearing frame glasses or contact lenses), dominant eye masking, visual training, strabismus correction (surgery), and restoration of binocular monocular function.