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distinguish between presbyopia and hypermetropia? |
Presbyopia Presbyopia describes the condition where the eye exhibits a progressively diminished ability to focus on near objects. It is a perfectly natural condition that eventually affects everyone but because the effects are gradual, you may not notice that anything is wrong with your eyesight initially. However, as the condition progresses, you may find yourself struggling to read small print or books unless they are held at arm's length. With presbyopia, there are many factors (such as deterioration of lens elasticity) that affect the eyes ability to accommodate over varying distances; causing light (and therefore images) to be focused behind the retina. This leads to the eyesight becoming blurred. Presbyopia can be easily corrected with glasses or contact lenses with a combination of options such as, varifocals, bi-focals, separate glasses or mono vision for contact lenses only. Mono-vision is where we correct one eye for distance and the other for reading. Hypermetropia (Hyperopia) - Long Sighted Hypermetropia means long sight and is where the image of a nearby object is formed behind the retina. This could be because the eye is too short, or the cornea or crystalline lens does not refract the light enough. A hypermetropic person may have blurred vision when looking at objects close to them, and clearer vision when looking at objects in the distance. By placing a convex (plus powered) lens in front of a hypermetropic eye, the image is moved forward and focuses correctly on the retina. |