Three Reasons Why You May Need Eyeglasses
Here is some information about common eye troubles for which you may need prescription specs
Myopia – Also known as short sightedness, near sightedness
Shortsighted people generally view well up close, but not at a distance. Distant objects appear blurred, whilst close objects are in focus.
DESCRIPTION
The eye ball is longer than usual, making the eye "too powerful." The image is focused at a point in front of the retina. The greater the degree of myopia, the shorter the distance at which the Myopic can focus clearly.
SOLUTION
Myopia can be corrected using a concave lens that is thinner in the centre and thick at the boundary. This type of lens system pushes the focal point back onto the retina and restores good vision at any distance.
HYPEROPIA – May be known by the terms long sightedness, far sightedness
Farsighted people see far better at a distance than close up. Even though distant objects are properly focused, the accommodation required to focus on close objects causes eyestrain.
DESCRIPTION
The eye ball is shorter than normal which means the eye is not powerful enough. The eye is said to be "too short" and the image is focused behind the retina.
SOLUTION
Hyperopia is corrected with a convex lens that is thin at the border and thick in the centre. This type of lens brings the focus forward to the retina.
ASTIGMATISM
People with astigmatism have poor near and distant vision. They do not sense the contrasts between horizontal, vertical and diagonal lines in the same way likened to those with regular eyes.
Astigmatism is always accompanied by an additional visual impairment, such as Myopia, hyperopia and Presbyopia.
DESCRIPTION
Astigmatism is usually a result of an irregularly-shaped cornea which is slightly oval, instead of round, and oblong as opposed to spherical.
SOLUTION
Astigmatism can usually be corrected with the use of a cylindrical lens whose curvature offsets the corneal irregularity.
