For those with a large difference in myopia in both eyes, one may consider wearing corneal contact lenses, also known as contact lenses, or keratomileusis for correction. For those who do not want to wear glasses, excimer laser or femtosecond laser surgery may be considered. In medical terms, a person with unequal refractive error in both eyes is called refractive error. Those with a difference of more than 250 diopters will usually have symptoms due to difficulty in fusing images and will show monocular dysfunction in both eyes, and will be prone to visual fatigue. Children with higher diopters are more likely to have amblyopia and cannot wear glasses that produce a fused image, so they cannot wear ordinary glasses.