Children's hypermetropia - Having long-sight

The medical term is…
Hypermetropia

But it’s often called…
Long-sight

Hypermetropia is a common problem with the eye’s focusing that can affect your vision at all distances, but especially close-up. Many very young children have mild hypermetropia that gets better by itself as they grow older.

Long sight can be easily corrected with glasses or contact lenses, or laser surgery for adults, can be used.

What does that word mean?

Hypermetropia comes from the Greek word hupermetros, where ‘huper’ means ‘beyond’ and ‘metros’ means ‘measure’ – beyond measure

How you see the world

If you have mild hypermetropia as a child, the natural lenses in your eyes are very flexible and will often change focus to compensate. But if you have a lot of hypermetropia or are older, you might get problems such as:

  • difficulty seeing things
  • eyes feel tired
  • problems with reading

How the world sees you

People with hypermetropia look normal, but they might wear glasses or contact lenses.

Is it common?

The percentage of people with hypermetropia increases with age. A study has shown that 13.2% of people who are between 20-25 years of age have hypermetropia. This increases to 17.4% for people who are between 40-45 years of age.

Why did I get it?

There is no known cause in most people with hypermetropia, but it may run in the family.

Rarely, hypermetropia can be caused by other conditions:

  • problems in the retina
  • microphthalmia, or small eye syndrome - where your eye(s) did not develop properly during your mother’s pregnancy

Hypermetropia is caused by a focusing problem. Think about it like this - when you watch a movie at the cinema, the film projector has to be focused to get a nice sharp picture on the screen. Light passes through your eye’s natural lens like it passes through the projector’s lens. Light then focuses on the retina at the back of your eye the way it focuses on the cinema screen.

Imagine if the distance between the projector and the screen was too short: the picture on the screen would be blurred. In hypermetropia, the length of your eyeball is too short for the strength of your eye’s lens. Light is focused too far back, behind the retina, and so things look blurred.

Light rays are focused too far behind the eye in hypermetropia

How can the doctor tell?

Hypermetropia is usually diagnosed with a simple glasses test using a special torch (retinoscope) and lenses to measure how your eye focuses.

Getting it sorted

Hypermetropia can usually be corrected with glasses or contact lenses. These are convex (curved outwards) lenses, which move the focus of the light forward onto the retina, allowing you to see clearly.

Laser surgery to correct hypermetropia is also available but is usually only used in adults, once the eye has stopped growing. It works by changing the shape of your cornea so that light is focused correctly.

 
 
  • Mild hypermetropia makes reading difficult
  • More hypermetropia makes both near and far things blurry
  • Children with severe hypermetropia will not develop good vision without glasses
 

When the going gets tough

Hypermetropia can make you 'over-focus' which can cause one eye to turn, called a squint. It can also cause the vision to not develop properly. This is called amblyopia (lazy eye) and you might need to wear a patch.

Moorfields Eye Hospital NHS Foundation Trust
City Road, London EC1V 2PD
Phone: 020 7253 3411
www.moorfields.nhs.uk

Moorfields Direct Telephone Helpline
Phone:
 020 7566 2345
Monday to Friday 09.00 to 16.30 for further information and advice. 

Last updated: 20th November 2017