Now a days everyone is using contact lens and they are in trend these days.Here are a few things about them,
HISTORY OF CONTACT LENSES
First contact lens was processed and introduced to the world as far back as 1887 which had two glass layers within which a substance, called ‘gilletine’ was inducted. But, at that time, there was no method to measure curve of the eye. But due to their heavy weight, such lenses could not gain prominence due to obvious factors. It was in 1943 that first plastic lens was processes and introduced to the medical world. The plastic contact lenses could be easily fitted on the front portion of the eyes and were called sclera contact lenses but could not gain popularity. Thereafter, corneal contact lenses were processes and introduced in the market in 1948. These lenses can be easily fitted over the transparent part of cornea and are quite easy to fit and remove, whenever necessary.
TYPES OF CONTACT LENSES
Three types of contact lenses / lens type are in use now a days, viz.,
- Hard contact lenses
- Soft contact lenses
- Semi-soft contact lenses
PURPOSE BEHIND USE OF CONTACT LENSES
- Cosmetic consideration
- To get rid of habitual wearing of glasses
- Easy to use, remove and maintain
- No fear of misplacement and loss
- Its use decreases number of eyesight (though not in all cases)
- Certain visual defects get automatically removed
- Provides better eyesight and visibility.
DISEASES WHICH NEED USE OF CONTACT LENSES
- Astigmatism ( defect of vision in which image of an object is distorted)
- Keratonconus (Conical cornea)
- Diplopia (Double vision)
- Anisometropia (a condition in which the power of refraction on one eye differs markedly from that in the other)
- Myopia (nearsightedness).
All the aforementioned and some other conditions are attempted to be rectified by use of contact lenses. Some problems and difficulties caused by use of spects are removed by use of contact lenses. A person which habitually uses spects has a field of vision shorter, especially when number of glasses is on the lighter side, but this defect is removed by use of contact lenses which move and rotate with the movement of eye, and one has not to exert his eye while looking through contact lenses.
It is also claimed that constant use of contact lens reduces the number and further additions to the number is stopped. But in some cases, the number continues to rise, despite use of contact lenses. Contact lenses are much easier to move and the young boys and girls always prefer to use them. In addition, they are spared the inferiority complex which is generally attributed to the use of spectacles.
