Corneal clear means normal, and in the ophthalmologist’s description of an eye exam, a cornea that is generally free of other pathologies is described by corneal clear or corneal transparency. The cornea is located at the very front of the eye, is transparent, avascular, and covered by the tear film. It is an important refractive interstitium, and is the pathway through which light from the outside world enters the eye. Whether the cornea is normal or not can not only observe whether it is transparent or not, the size of the cornea is also one aspect, if the cornea diameter is too large or too small, it is a pathologically large cornea or pathologically small cornea. Normally, the cornea is thinner in the center and thicker in the periphery. If the thickness of the cornea changes, refractive problems will appear and also suggest the presence of pathology. Patients with corneal anomalies are advised to seek prompt medical attention to evaluate their condition and to follow their doctor’s instructions.