NANDANA J NAIR

A BIOMATERIAL is a substance that has been engineered to interact with biological systems for a medical purpose, either a therapeutic or a diagnostic one. Biomaterials are materials meant to be cut into the body to replace or repair damaged organs or tissues. The science that deals with the study of biomaterials is known as biomaterials science.

CONTACT LENSES AND THEIR HISTORY: 

Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes People prefer wearing contact lenses for a number of reasons. Firstly due to the comfort it provides.Secondly, based on aesthetic and cosmetic reasons. Others wear contact lenses for functional or optical reasons too.

The famous scientist, Da Vinci came up with the first known sketches of a concept that suggested that human eyesight could be altered by placing the cornea directly in fluid medium. Later after hundreds of years, the well-renowned technology of the easily usable contact lenses that we now use flourished.Contact lenses are classified in diverse ways:- by their primary function, material, wear schedule (how long to be worn and to be removed) and replacement schedule (after how long a lens has to be discarded).

TECHNOLOGY USED IN BIOMATERIALS IN CONTACT LENSES:

Soft contact lens { SCL} bio-materials originated from the discovery of a poly{2-hydroxyethyl methacrylate} {poly[HEMA] based hydro-gel in 1961.Incorporation of hydrophilic polymers into poly[HEMA] hydro-gels was performed in the 1970-1980s which brought an rise in the equilibrium water content, leading to an enhancement of the oxygen permeability.

Nowadays the poly [ HEMA] based hydro-gels have been applied in disposable SCL. At the same time, high oxygen permeable silicone hydrogels were produced, which made it conceivable to continually wear SCL. Recently numerous trials for improving the water wettability of silicon hydro-gels have been performed. However little attention has been paid to rising their anti-biofouling properties and biocompatibility. Since bio-mimetic phospho-lipid polymers contains excellent anti-biofouling properties and biocompatibility, they can play a valuable role in the surface modification of the silicone hydrogel.

ROLE THAT A CONTACT LENS PLAY:

Correction of refractive error :

Corrective contact lenses are designed to improve the quality of vision, most commonly by correcting refractive errors. This is done by directly focusing light so it enters the eye with the proper power for clear and focussed vision.

Aspherical contact lens bends light evenly in every direction (horizontally, vertically, etc.). They are typically used to correct myopic and hypermetropic defect of the eye.

Contact lenses can also correct astigmatism and presbyopia[defect where both far vision and near vision are affected].

CONCLUSION:

Contact lenses have been used by more than 150 million people all over the world.

With the development of new contact lenses for a variation of consumers, the number of wearers has gradually increased over time. With the continuous advancement of research in this field, there is high hope for contact lenses to be used as an ocular drug delivery system for the masses. In the long term, this means that contact lenses could ideally provide a great platform for managing conditions such as glaucoma, allergy, and other photosensitive conditions. Its easy and comfortable usage makes it a great bio-material in the scientific world.