Source:http://linkedlifedata.com/resource/umls/id/C0034951
MSH: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.,CSP: blurred vision caused by the eye focusing light either behind or in front of the retina.,MEDLINEPLUS: <p>Your cornea is the clear front part of your eye. It is like a window that controls and focuses the light coming into the eye. If your cornea has an irregular shape, the light does not focus properly. Everything looks blurry. This is a refractive error. </p><p>Four common refractive errors are</p><ul> <li>Myopia, or nearsightedness - clear vision close up but blurry in the distance </li><li> Hyperopia, or farsightedness - clear vision in the distance but blurry close up</li><li> Presbyopia - inability to focus close up as a result of aging</li><li> Astigmatism - focus problems caused by the cornea</li></ul><p>Glasses or contact lenses can usually correct refractive errors. Laser eye surgery may also be a possibility.</p><p style="font-weight:bold;font-style:italic;">NIH: National