Having your eyesight regularly tested will ensure that any vision defects, such as nearsighted or short-sightedness or myopia can be corrected.
What is nearsighted?
Normal, healthy eyes have the ability to focus on a broad range of distances from far away down to a few centimeters.
However, nearsighted (myopia) is a common defect of sight. This is a condition when one or both eyes have difficulty in seeing distant objects clearly.
The most common nearsighted are called simple myopia and tend to be passed down from one generation to another.
It usually starts around puberty and increases progressively until the early twenties, when the condition stabilizes. Simple myopia can also sometimes commenced in the early twenties, although this is unusual.
Myopia which develops in early childhood often continues to deteriorate and may become quite severe later in life.
Often, there are no symptoms to indicate poor vision. However, indicators include Difficulty recognizing people or objects from a distance.
The difficulty is reading words on the television screen.
Occasional headaches due to eyestrain.
What causes nearsighted?
In the normal vision, the light passes through the cornea (front of the eye) and the pupil. The image becomes focused on the retina (at the back of the eye) by the combined focusing power of the cornea and the lens.
The retina then converts this image into nervous impulses, which travel along the optic nerve to the brain.
In a myopic eye, the eyeball is too long, so that the focusing power of the cornea and lens are too loud about the length of the eyeball, even when the lens is adjusted to its minimum thinness. As a result, the image falls in front of the retina and so appears blurred.
Sudden loss or blurring of vision are not signs of shortsightedness and require urgent medical attention. Untreated nearsighted in children can lead to learning difficulties.
How is shortsighted diagnosed and treated?
Short-sightedness or myopia or myopic usually occurs in children.
Signs include difficulty in reading the blackboard at school and sitting very close to the television.
If the defect is only present in one eye, the right eye can be used without difficulty.
The problem can then only be detected by vision testing, particularly since simple myopia only rarely causes headaches or eye strain. Vision tests can be carried out by your GP or ophthalmic”optician (optometrist).
One simple test involves the use of a retinoscope, an instrument that shines a moving light beam through the pupil onto the retina at the back of the eye. Some light bounces back and moves when the retinoscope is moved.
The direction of movement indicates whether correction for short sight is needed. A further test involves reading from a standardized chart of letters of diminishing size, each eye being examined individually.
Average vision, described as 6/6, means that the letters on the bottom line can be read from 6m away. Short sight is shown by the inability to read these letters without spectacles and is described, for example, as 6/9 or 6/12, depending on which size of messages can be read.
Nearsighted is treated by wearing either glasses or contact lenses. In general, the higher the degree of shortsightedness, the greater the benefit of contact lenses, but they are also often worn for cosmetic reasons.
While spectacles need not be worn all the time, but only when they are required, it is a fallacy that continuous correction of eyesight weakens the eyes. Glasses and contact lenses can be provided either by the optometrist who examined your eyes or by an ophthalmic optician (who should always be registered).
A new surgical technique, using the excimer laser, can be used to correct moderate degrees of myopia and appears to be safe. This is rapidly gaining acceptance.
When should I have my eyes tested?
Children usually have their eyes checked before school entry by their GP or school medical officer, and this may be repeated before secondary education. Particular attention should be paid to the vision of the brothers or sisters of a blind child. Adults are advised to have their eyes tested every two years.
A checkup is always worthwhile, even if you do not have any of the symptoms such as frequent headaches, tired or strained eyes, blurred vision, or sudden loss of vision.
It is essential for drivers to have their eyes checked regularly. Driving with vision below the minimum standard of being able to read a number plate at a distance of 20m is illegal and dangerous.
Most adults now have to pay for a full examination by an optometrist.
Children under 16 and those in full-time education up to the age of 19 are entitled to free tests.
What can I do myself?
If you are nearsighted, it is important to have regular eye checks so that any deterioration can be corrected. Never buy ready-made spectacles without a prescription, they are not suitable for shortsightedness.
They are sold only as reading glasses and have same lenses in each eye. It is important to detect shortsightedness in children, especially if it is severe. If one-sided and untreated it can result in amblyopia (lazy eye)
which can reduce the look’s accuracy of vision?
What can I do to avoid nearsighted?
Nothing can be done to prevent shortsightedness, but the wearing of appropriate spectacles or contact lenses and regular checks will ensure that visual impairment is minimized.
You can help to avoid straining your eyes by the taking care that sufficient light is provided for reading and doing close work, and by ensuring that you do not look at VDU and television screens for long, uninterrupted periods.
Is short-sightedness dangerous?
Shortsightedness is not, in itself, dangerous, provided that you always wear
spectacles or contact lenses when driving.
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