Tuesday, 28 February 2017

REFRACTIVE ERRORS

HYPERMETROPIA OR LONG SIGHTEDNESS 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 is too flat or it may be because of medications or it may be because of dislocation or absence of lens.




A hypermetropic person has blurred vision for near objects and clear vision for distance object.As the condition worsens ,objects at all distances may be blurred.

ASTIGMATISM

When the cornea has an irregular shape,it is called corneal astigmatism.When 
the shape of the lens is distorted it is called lenticular astigmatism.As a result your vision for both far and near objects appear blurry or distorted.It can be a sign of keratoconus.







SYMPTOMS of hyperopia and astigmatism include

Headache
Eye strain
Squinting of eyes(because of excessive accommodation)

Treatment for both type of refractive error includes spectacles,contact lens,refractive surgery.


PRESBYOPIA is a condition associated with aging of the eye that results in progressively worsening ability to focus clearly on close objects.The ability to focus on near objects declines with increasing age.










REFRACTIVE ERROR