Optics & Refraction

Presbyopia affects 1.8 billion people worldwide, according to the World Health Organization (WHO). The American Academy of Ophthalmology (AAO) describes it as a common age-related decline in the eye’s near…

An exam that uses a magnifying lens and a light to check the posterior segment of the eye, including the retina and optic nerve is called Fundus Examination. It is…

Retinoscopy is also known as skiascopy, shadow test or pupilloscopy or koreoscopy. It was introduced by Bowman in 1859. It is an objective method of finding out the error of…

What is the meaning of Refractometry ? It is the estimation of refractive error with a machine called refractometer or optometer. Autorefractometry An autorefractor is an alternative method of finding…

With the rapid development in electronics and micro computers a number of innovative methods & instrument for automated clinical refraction have appeared since 1960. Refractometer is used to determine the…

WHAT IS RETINOSCOPY RETINOSOPY also called as skiascopy or shadow test is an objective method of finding out the error of refraction by the method of neutralization. PRINCIPAL RETINOSCOPY is…

Before we discuss the optics of myopia we should acknowledge the laypersons terms for myopia. Myopia means I shut the eye; the term was introduced from the habit of half…

This is a fact that we cannot see any object in a perfectly dark room conclusively establishes the truth that light is necessary for the purpose of vision. Nature has…

Light is a form of energy or a composed of particles of photons. The photon Particles are actually massless bundles of concentrated electro magnetic energy that are travels in a…

The transmission of Light is defined as the moving of the electromagnetic waves through a material. Visible light is the cause we are able to see anything at all. Transmission…