Hypermetropia – Causes, diagnosis and preventionReading Mode
Hypermetropia or farsightedness is a common refractive error of the eyes. In this situation the person has no problem with distant vision but cannot see objects at a close range very well.
Normally, the rays of light enter the eye through the cornea and converge at the back of the eye at its innermost layer called retina. If the curvature of the cornea is less than normal or the eye is shorter than normal, the light rays are focused behind the retina leading to blurred near vision.
Causes of hypermetropia
- Heredity is a common cause and people whose parents have this problem are likely to develop it.
- Longsightedness is usually present at birth and can be detected in a child during routine health check-ups and health camps in school.
Symptoms and signs of hypermetropia
- Eyestrain is a symptom when looking at near objects or reading or doing needlework.
- The person may develop crossed eyes or squint.
- Headaches may be present.
- Night vision is adversely affected.
- A child may get frustrated as he cannot see his books clearly and hence may have difficulty in reading and writing.
Diagnosis of hypermetropia
Hypermetropia can be diagnosed in an infant or child by their paediatrician. Adults are diagnosed by ophthalmologists who will also rule out other eye conditions by doing a complete eye examination.
Treatment of hypermetropia
Conservative treatment includes using spectacles or glasses or alternatively, contact lenses.
Some people with mild hypermetropia may not need any treatment as the lens inside the eye is flexible and compensates for the problem. This is called accommodation. However, with age the lens becomes less flexible and then the problem comes to light.
- Several techniques are available to correct this problem, but it should be reserved for severe cases of hypermetropia.
- LASIK (laser assisted in situ keratomilieusis - The cornea can be reshaped using LASIK so that light falls on the retina. This is done by cutting a small cornea flap and removing few layers of the cornea to create a dome shape and then repositioning the flap in place.
- PRK (photo refractive keratectomy) - In this procedure the thin covering called epithelium over the cornea is removed and then it is reshaped.
- Conductive keratplasty - In this temporary method, radiofrequency is used to heat certain areas of the cornea.
Prevention of hypermetropia
- If you have a history of farsightedness be sure to get your eyes checked at regular intervals even before you turn forty.
- Don’t smoke and eat a balanced diet for good eye health.
- If you have trouble seeing nearby objects, schedule an appointment with your eye doctor promptly. Do not drive till you get your eyes checked.
- Wear sunglasses that block ultraviolet rays of the sun.
- If you have diabetes or hypertension, keep them in check with regular check-ups.
Photograph via Creative Commons
Written by Dr Nisreen Nakhoda, General Physician
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