Contact lens vision correction – is the use of contact lenses to correct the visual organ pathology. On medical indications contact lenses should be used if vision correction with glasses is ineffective. They are also prescribed for professional and cosmetic reasons.
What are positive aspects of contact lens?
Contact lenses rest directly on the cornea of the eyeball, as though they complete the cornea, making a single optical system. Therefore, light rays are refracted only by the lens anterior surface and then pass through homogeneous (with respect to refraction) optical ocular medium. The resulting image has much less distortion. In addition, contact lenses do not limit the field of vision. Most contact lenses practically block the transmission of ultraviolet light. Contact lenses make your sense of sight more natural and do not affect the field of view.
Real progress in contact lens vision correction started at the beginning of this century due to the advent of convenient and safe contact lenses in the market. Presently contact lenses are made of different materials. Depending on the material, contact lenses can be hard (HCL) and soft (SCL). Soft contact lenses are more easy to use, they are distinguished by elasticity, gas permeability and hydrophilic ability.
There are many indications for contact lens vision correction: myopia, hyperopia, astigmatism, anisometropia, aphacia, corneal diseases etc. Patients who have in their case history frequent inflammatory diseases of eyelids, conjunctiva and other structures of the eye, allergic conjunctivitis, blepharitis, dry eye syndrome, either moderate or severe, as well as Sjogren disease cannot wear contact lenses.
For proper fitting of contact lens the ophthalmologist’s advice is required. After a comprehensive examination of your eyes the doctor will make a decision on the possibility of application of this type of correction.
Fitting of contact lenses may be divided into primary and repeated.
Primary contact lens fitting requires a comprehensive eye examination. The procedures include estimation of visual acuity of each eye, ocular refraction, state of accommodation, testing of the shape, thickness and sensitivity of the cornea, the amount and composition of tears, the patency of lacrimal passages as well as fundus of the eye examination. With the help of optical instruments eyelids are examined to prevent their inflammation. Only after a thorough examination of the visual organ, the doctor will prescribe you certain contact lenses and will definitely teach the patient how to use and take care of them.
Proper fitting of contact lenses can be determined by your own perceptions: you should feel comfortable and notice an improvement in your vision.
Repeated fitting of contact lenses is required for the change to stronger or weaker lenses.
However, this will not be your final visit to the doctor. People who wear contact lenses should regularly consult an ophthalmologist. This will allow them to avoid complications that usually occur as a result of violation of the instructions for wearing contact lenses, non-compliance with the rules of storage, manipulation and hygiene, lens damage etc. In the period of adaptation which lasts about a month you should consult an ophthalmologist biweekly or as inconveniences arise and then every six months.