Nearsighted/Farsighted, Huh? All Greek to Me!!

When speaking about vision and eyes, there are some common terms that we should discuss.

We often hear the terms nearsighted or farsighted.  But what do they really mean?

NEARSIGHTED

If you are Nearsighted, this simply means you  have trouble seeing clearly in the distance but close-up objects are clear.   The optical term for this condition is Myopia. 



NEARSIGHTED--MYOPIC EYE

A more in depth explanation is that when light enters into the eye from a distant object, it should focus the light rays on the retina once passing through the lens of the eye.   However, in this condition, the light rays focus in front of the retina.  There are a few reasons for this.  It can be that the eye is too long, or that the eye has too much optical power.  I will get into this bit later on.

This condition can easily be corrected by a licensed optician fitting the patient with corrective lenses.  A Minus lens (concave) when placed in front of the myopic eye, can help to extend the light rays from the image to fall on the retina behind the eye thus having a sharp, clear image of the object in sight.

 

FARSIGHTED

 

If you are farsighted, this simply means that you have trouble seeing objects clearly close up and that distant objects are more clear.    The optical term for this condition is Hyperopia or Hypermetropia.

 

FARSIGHTED-HYPEROPIC EYE

 

 

 

When light enters into the eye from a distant object, it should focus the light rays on the retina once passing through the lens of the eye.  However, in this condition, the light rays focus behind the retina thus the image is formed behind the retina.

 

In this condition, a Plus lens or Convex lens is required to help light rays shift and from behind the retina and on to the retina.

 

We will discuss the parts of the eye in the next blog.