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.
- 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).
- 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 long-sight and short-sight can run in families and both are easily treated with glasses or contact lenses
This information is provided by the College of Optometrists. The College – a registered charity – is the professional body for optometry in the UK, working for the public benefit. It is a membership organisation and the most qualified practising optometrists in the UK are members. Membership of the College shows a commitment to the very highest clinical, ethical and professional standards. Look for the letters MCOptom or FCOptom to see if your optometrist is a member.