Refractive errors (ametropia) are the optical defects of eye in which the parallel rays of light entering the eye do not come to focus on the fovea centralis. Ametropia includes myopia, hypermetropia and astigmatism.

Clinical features:

Hypermetropia (hyperopia) or long-sightedness is the refractive state of the eye wherein parallel rays of light coming from infinity are focused behind the retina with accommodation being at rest. Symptoms include astheopic symptoms (tiredness and watering of eyes, frontal headache) and defective vision, more for near vision.

Myopia or short-sightedness is a type of refractive error in which parallel rays of light coming from infinity are focused in front of the retina when accommodation is at rest.

Astigmatism - The optical power of the cornea in different planes is not equal. Parallel rays of light passing through these different planes are brought to different points of focus.

Surgical treatment:

1.       No pharmacological treatment is available for ametropia.

2.       Accurate retinoscopy and corrective spectacles or contact lens. Keratorefractive surgery