Astigmatism is one ametropy types at which light rays are unable to focus on the retina. A healthy human eye has the cornea and the crystalline lens which have as a whole a form very close to spherical
The term myopia comes from Greek myops which means “screwing up eyes”. According to statistics, myopia, i.e. nearsightedness is suffered by every three people on Earth. This pathology of eye refraction is shown with a decrease in visual acuity.