Intraocular lenses are the kind of artificial lenses that can be used to replace the natural lens during the cataract surgery. Earlier after this surgery thick spectacles were required to be worn by the patients but with the advent of IOLs, the patient need not worry about the eyeglasses and are ensured good vision thereafter. IOLs were introduced in the 1960s but the formal FDA approval was received in 1980s.

The different types of IOLs are:

Multifocal or Accommodating IOLs: These lenses allow the patient to view objects at different distances and are not restricted to a single distance. Hence, while using multifocal lenses, additional eyeglasses or other lenses are not required.

Monovision: This is one of the interesting kinds of lenses. In this type each eye can be fitted with monovision lenses. In one eye, the lens implanted may provide near vision whereas in the other eye it may provide faraway vision. But this poses another problem that the eyes don't seem to work as they did initially because of the difference in vision.

Toric IOLs: These IOLs are mainly used to correct astigmatism. It is caused by an irregular shape of the cornea which maybe caused by eyeglasses, lenses etc. However, the disadvantage of toric IOLs is poor vision which maybe caused due to rotating lens. This may lead to further surgery for repositioning or replacement of the IOL.

Aspheric IOLs: The traditional IOLs are generally spherical in shape. But the aspheric, as the name suggests, are slightly flatter in periphery than traditional ones.

Blue-light filtering IOLs:It is generally believed that blue light causes damages to the retina. But with these lenses blue light as well as the ultra violet light can be filtered thus avoiding any damage to the eyes.

Piggyback IOLs: These IOLs are placed over the already existing IOLs. This is done in case the result is not proven to be correct or as expected. This approach is considered to be a safer one as compared to removing or replacing the IOLs.

The above mentioned types of IOLs are made from synthetic material.

The IOL implantation procedure usually requires about three to four hours. Initially the patient's eyes are subjected to anesthesia. Then a tiny hole is made near the edge of the eye. Through this hole the cataract is removed. The IOL is implanted through the same hole. This surgery has benefited a number of patients. The patients have shown remarkable improvement as regards their vision. Also the need for extra lenses or glasses is eliminated. The surgery is a bit costly but is effective for the rest of the life.

The IOL implantation certainly had a number of advantages but also has a handful of disadvantages. They are minor infection, swelling in the eye, the centre of the lens may move, power can be calculated wrongly, retina detachment etc. but through proper checking of eyes and risky optical surgery can be avoided. Thus the surgery proves to be a boon if carried out with care and expertise.