oRIGIN OF THE WORD. It comes from the Greek word muōps meaning short-sighted these people cannot see distant objects clearly.ANATOMY Before we can describe myopia let’s compare the eyeball to a camera for better understanding. When we take a picture, light after reflecting from an object enters the camera and passes through the following; Firstly, it passes a transparent glass in front of the aperture of the camera. Then secondly, it passes a Camera lens that helps us in focusing light rays and lastly, there is a Camera film on which light is focused on a clear picture.

Eye is somewhat similar as when we see an object, light after reflection from that  object enters our eye through; Firstly, it passes cornea (the transparent curved front part of eye) then secondly, it passes through the crystalline lens that helps us in focusing light rays and lastly, there is the retina (light-sensitive receptor cells in the posterior part of eyeball) on which light is focused for a clear image. Definition of Myopia It is a form of refractive error (inability to refract/ bend/focus the light rays properly) in which parallel rays of light(i.e.Coming from a distinct object) after entering the eye are focused in front of the retina instead of on retina with eye muscles at rest causes: Curvature: increase of curvature of cornea or lens causes light rays to be focused in front of retina and hence myopia occurs. Axial: increase in axial length of eye, increases the converging power and cause light raysto be focused in front of retina Index: increase in refractive index (i.e.light bending/focusing power) of the lens (For example in cataract)Positional: anterior displacement of lens e.g. after trauma this again causes lightrays to be focused in front of retinaTYPES Congenital: from birthSimple: most common, starts from 5-10 years till 20-15 years and is mostly due to curvatureor length problem of eye ball Pathological: hereditary, progressive andis due to degenerative changes in the eyesCLINICAL FEATURES SYMPTOMSBlurred vision Half shutting of eyes (parents of child willtell) Outward deviation of eye (Divergent squint)(normal pts require to move their eyes inward while focusing near objects this is not requiredin myopic pts causing their eye to move out intermittently or constantly)SIGNS Prominent eye ball (as eye is big)Retinal changes (in pathological myopia) DIAGNOSIS Retinoscopy (a hand-held device that throwslight in the eye and allowing us to observe its movements and reflection, hence helpingto confirm the refractive error) A-scan (a small ultrasound probe that throwsUltrasound waves in the eye ball and then detects their reflections or echo timings,calculating the eye ball length) TREATMENT Unlike the camera, maximum (2/3rd) focusing in an eye is done by the transparent frontpart(cornea) while the rest (1/3rd) is done by the lens. So, while treating these patients we have to decrease the focusing power of the eyes that image is formed on the retina instead of in front of it. This can be done by using either a diverging lens like glasses Contact lenses some surgical procedure can be done to reduce the focusing power of either the cornea or the lens so that image forms on Retina instead of in front of it. SURGICAL TREATMENT Flattening the central part of the cornea. This includes different methods that were changed and advanced depending upon the reduction of side effects and recovery time and improvement of the degree of vision.

The surgeries included in this category are :

Radial keratotomy
Photorefractive keratectomy

LASEK: laser epithelial keratomileusis
LASIK: Laser In-situ Keratomileusis

Other Surgical Treatment options are:Lens extraction
Contact lens implantation