Myopia

Myopia or short-sightedness refers to a defect in the vision. It happens when the eye is too long from the front to back, or too sharply curved from the cornea. This results in a variance between the focusing power of the lens and cornea and the length of the eye. It leads to a blurred vision of distant objects and a clear vision of the close objects. The range of Myopia can be classified as mild, medium or high degree. High degree Myopia (or Pathological Myopia) often causes problems later in life as it is connected with the changes in the back of the eye.
Symptoms of Myopia
Myopia mostly takes place sometime around puberty, but can happen at any time between childhood and the age of 25. Initially the children who have been afflicted by Myopia don’t even realize that their vision is blurred. The earlier it starts, the worse it tends to get with time. Some of the most common symptoms of Myopia have been listed below.
The objects that are at a distance look blurred.
Headache
Exhausted eyes
Causes of Myopia
Myopia runs in families. If even one of the parents has it, the child has 30% chances of getting it too. If both the parents have it, there are over 50% chances of the child getting it too. Several factors join to cause Myopia, like a person’s genes, the surroundings and how much his/her body has been afflicted by it.
Diagnosis of Myopia (or Short – sightedness)
A simple eye and vision test using a Snellen chart (eye chart) is done to diagnose Myopia. The Snellen chart consists of rows of alphabets and numbers of different sizes. The level of one’s eyesight is measured by the tiniest line of letters that the person can read from a distance of six metres.
Treatment of Myopia
A pair of spectacles/glasses or contact lenses are used to correct Myopia. These rectify the sharp curve of the cornea or the excessive length of the eye in order to clarify the vision of distant objects. Several surgeries to treat Myopia are available. In these, the surgeon rectifies the shape of the cornea so that the focus of the eye becomes correct. A few existing surgical procedures have been listed below:
Laser in–situ keratomileusis (LASIK) – in this operation, a tiny opening is made in the cornea, and a small piece of the tissue is removed using a laser. This surgery is carried out as an out-patient process. It takes about 15 minutes to perform on each eye. After the surgery, eyesight may be foggy or fuzzy for a couple of days. This is the latest treatment for short-sightedness and is a long-termed one. The effectiveness of this procedure has not yet been proved.
Photorefractive keratectomy (PKR) – in this operation, a tissue is removed from the cornea, reshaped and placed back using a laser. It is quite painful for about 48 hours after it is done. This can be done only when the Myopia is less severe.
Radial keratotomy – in this operation many cuts are made in the cornea using a diamond shaped scalpel. This procedure takes about 15 minutes to complete and is not all that painful. It is used to treat less severe Myopia.
Since the use of glasses or contact lenses can be used o rectify Myopia, it is advised by the NICE that the above mentioned surgeries shall not be routinely done.
Complications of the surgeries
Clouding of the cornea
Over correction leading to long-sightedness
Retinal detachment
Cornea or eyeball puncture
Glaucoma
Cornea infections
Glare around bright lights