The causes of hypermetropia or long sightedness defect of vision are :
- Shortening of eye ball
- increase in focal length of eye lens
- failure of ciliary muscle to contract the lens.
Hypermetropia (long-sightedness) is a common eye condition where nearby objects appear blurred, but your vision is clearer when looking at things further away. If you feel your eyes are often tired and you have problems focusing on objects close to your eyes, you may have hypermetropia. A person with hypermetropia/hyperopia or long sight can see clearly objects far away from them, but not close to them. This is caused by the shape of the eye - the eyeball is slightly too short. It is corrected by spectacles or contact lenses with lenses which are 'plus' or convex in shape.There are many causes for this condition. It may occur when the axial length of eyeball is too short, or if the lens or cornea is flatter than normal. Changes in refractive index of lens, alterations in position of the lens or absence of lens are the other main causes.
In hypermetropia, the cornea is flatter or the axial length is too short. Therefore, the images do not focus by the time they reach to the retina. For clear vision, a hypermetropic eye must accommodate to increase its lenticular power to bring distant objects in focus on retina.Most commonly, farsightedness is caused by a cornea (clear layer at the front of the eye) that isn't curved enough, or by an eyeball that's too short. These two problems prevent light from focusing directly on the retina. Instead, light focuses behind the retina, which makes close-up objects look blurry.
- Have your eyes checked. ...
- Control chronic health conditions. ...
- Protect your eyes from the sun. ...
- Prevent eye injuries. ...
- Eat healthy foods. ...
- Don't smoke. ...
- Use the right corrective lenses. ...
- Use good lighting.