Summary   Summary
Featured Diseases & Conditions
Health Awareness Articles
Articles
Symptom Checker

Symptom Checker
Just click on a body part, choose your symptom and search through a world of health information.

 

Search Diseases

Search Disease

Hyperopia


Overview :

When light goes through transparent but dense material like the materials of the eye's lens system (the lens and cornea), its velocity decreases. If the surface of the dense material is not perpendicular to the incoming light, as is the case with the curved surfaces on lenses and corneas, the direction of the light changes. The greater the curvature of the lens system, the greater the change in the direction of the light.

When parallel light rays from an object go through the lens system of the eye, they are bent so they converge at a point some distance behind the lens. With perfect vision this point of convergence, where the light rays are focused, is on the retina. This happens when the cumulative curvature of the lens plus cornea and the distance from the lens to the retina are just right for each other. The condition where the point of focus of parallel light rays from an object is behind the retina is called hyperopia. This condition exists when the combined curvature of the lens and cornea is insufficient (e.g., flatter than needed for the length of the eyeball). This condition can be equivalently described by saying hyperopia exists when the eyeball is too short for the curvature of its lens system.

There is a connection between the focusing of the lens of the eye (accommodation) and convergence of the eyes (the two eyes turning in to point at a close object). The best example is during reading. The lens accommodates to make the close-up material clear and the eyes turn in to look at the print and keep it single. Because of this connection between accommodation and convergence, if the lens needs to accommodate to focus for distance (to bring the image back onto the retina) the eyes may appear to turn in even when looking at the distance. This can cause a condition known as accommodative esotropia in children. The eyes turn in and the cause is accommodation because of hyperopia.




 Image Gallary
 
Search for information related to Health and wellness
Health Centers
Cardiology and HeartMen's HealthWomen's HealthMother + ChildDiabetesStressInfectious DiseaseSkinEyeCancerStop SmokingWeight ManagementSexual HealthBlood Pressure ManagementAsthmaPregnancy and Child BirthAllergyHair LossDengueCold and FluSore ThroatADHDDental & Oral HealthHigh CholesterolDepressionPolioBreast CancerFood PoisonSnoringConjunctivitisCervical CancerJaundiceGeneral HealthMigraine / HeadacheThyroidBlood SugarProstate CancerKidney DiseaseAnxietyArthritisAutismBipolar DisorderCOPDCaregivingCrohn's DiseaseEpilepsyErectile DysfunctionHealthy AgingIncontinenceMeningitisMenopauseMultiple SclerosisOsteoporosisPain ManagementParkinson's DiseaseRelationshipsSleep ManagementStomach & DigestiveOsteoarthritisPertussisOveractive BladderRheumatoid ArthritisTonsils
Search for information related to Health and wellness
 
Health Pages
blood pressure cancer cholesterol test diabetes diets erectile dysfunction hair loss health health articles healthy living heart diseases high cholesterol pregnancy reduce weight vagina weight wellness health plan sexual problems lower cholesterol heart attack women health asthma weight loss anxiety back problems disease symptoms immunization for children indian home remedies indian recipes Manage weight pathology tests stress enhancement herbs best fish for heart health saturated fat cholesterol bird flu cure types of abortion procedures thickening breast Dysentery abortion survivor signs of prostate cancer Dextromethorphan Ammonium chloride bromohexine low triglyceride level stress and heart disease for and against abortion dental health activity pages heart health campaign