Long and short-sightedness

The light coming in to the eye needs to be focused on the back of the eye (the retina) for you to see clearly.

Long-sightedness (hyperopia)
Some people have eyes that are too short, which means the light focuses behind the retina (they are long-sighted). This means that they have to focus more than they should do, particularly on things that are close up.

An illustration of long-sightedness

 

The video below should be viewed in conjunction with the text beneath it and preferably watched while your optometrist discusses it with you.

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  • Normally, light is focussed by the cornea and lens to form a sharp image on the retina.
  • Long-sightedness occurs when the eyeball is slightly too short
  • … so that objects are in focus behind the retina at the back of the eye.
  • This may result in blurred vision when looking in the distance
  • …and particularly when looking at near objects and reading.
  • When we are young, we overcome long-sightedness by bulging out the lens in the eye.
  • However, as we get older, the lens gets harder and can no longer bulge out enough.
  • Long-sightedness can be corrected by glasses or contact lenses.

 

 

Short-sightedness (myopia)
Other people have eyes that are too long, so the light focuses in front of the retina (they are short-sighted). This means that they cannot see things clearly if they are far away from them (such as the TV or board at school).

An illustration of short-sightedness

 

The video below should be viewed in conjunction with the text beneath it and preferably watched while your optometrist discusses it with you.

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  • Normally, light is focussed by the cornea and lens to form a sharp image on the retina.
  • Sometimes the eyeball is too long for the shape of the cornea
  • … so the light comes to a focus before it reaches the retina.
  • As a result, objects in the distance are blurred
  • … although close objects are usually clear.
  • Short-sightedness can be corrected by glasses or contact lenses.
  • These lenses correct the vision so that distant objects are clear once again.

Both conditions can run in families and both are easily treated with glasses.