Keratoconus is a non-inflammatory, degenerative, self-limiting ectactic disease of the cornea characterised by progressive thinning and steepening of the central cornea giving rise to a cone shape. This cone prevents light from focusing on the macula. As the disease progresses it gives rise to high irregular astigmatism and the patient experiences gradual deterioration of vision. This is a common disorder and its incidence varies across racial groups with a female preponderance, namely, 57 to 67 percent. Although the condition is more common in some families, most cases are sporadic, and no pattern of inheritance is apparent. The onset of the disease is usually at puberty (teenage years) and always manifests in the first three decades of life. Keratometer is a simple tool for measuring the central curvature of the cornea. In the initial stage it is difficult to superimpose the keratometric rings which are a “hallmark” for keratoconus. This testing can also detect inferior steepening of the cornea. Keratometric signs include mal-alignment, mal-aposition, mal-focusing, mal-shaping, mal-sizing and pulsation of the mires.