What You Should Know About Cataract

Before understanding what cataract is all about, you need to know the structure in the eye that is involved in cataract formation.

The lens is a transparent, biconvex, crystalline structure in the eyes that causes light coming from a viewing object to bend so that they converge at the back surface of the eye (the retina) were they elicit visual information which are carried to the brain for interpretation. The lens is surrounded by a thin transparent membrane which is thicker over the anterior surface than the posterior surface of the lens. This membrane is called the lens capsule. 

Immediately beneath the anterior lens capsule lies the anterior epithelium which is absent at the posterior part of the lens. The anterior epithelium are proliferative in nature (they produce new cells) and during this process of proliferation, the old epithelial cells elongate to form lens fibers which fills the central part of the lens. This process continues throughout life, hence as new epithelial cells are formed, the old ones are pushed towards the cortex and nucleus of the lens (after the epithelium, the cortex and then the nucleus).  As this process continues, the lens nucleus becomes compressed, thick and hard (nuclear sclerosis) which often appears yellow.

Although other conditions like trauma, radiation, medications, etc have been proven to cause cataract, aging is considered as the common cause. This is because as one ages, progressive oxidation damages the lens and this process is accelerated by diseases (such as diabetes mellitus and hypertension), toxins, radiations and ultraviolet rays (sun).

Blunt trauma (eye injury) may cause the lens to swell up, thicken and become white (opaque). However, the swelling usually resolves with time but the white structure in the lens may remain leading to induced cataract. If the blunt trauma is severe and penetrates the eye, it may damage the lens capsule, which enables fluids to enter the lens leading to swelling and opacification (which prevents light from passing through). 

Studies have shown that radiations, specifically ultraviolet light (the sun) causes cataract in the same way the transparent part of an egg turns white when cooked and wearing of sunglasses prescribed by optometrists at early age can slow its development in later life.

Another study has proven that cigarette smoking can increase the risk of developing cataract up to two to three times than a non-smoker. This is because cigarette contains free radicals that cause oxidative damages in the lens fibers.

Wearing of sunglasses prescribed by eye doctors (optometrists and ophthalmologists) prevents ultraviolet rays that damages the eye from entering and since cataract is a degenerative process caused by oxidative damage, intake of antioxidants (especially the carotenoids) will help slow down the process.

The only treatment option for cataract is surgical removal of the opaque lens (when the cataract has matured) and replacement with intraocular lens material. However, N-Acetycarnosine drops is still under investigation. This eye drop is believed to work by reducing the lens oxidative damage. 

The best option is to prevent the cataract from occurring by taking dietary antioxidants and their supplements and by wearing sunglasses prescribed by eye doctors especially when carrying out our daily activities under the sun. Furthermore, you should try as much as possible to avoid cigarette smoking.