Cataract forms when the crystalline lens of the eye develops an opacification. Lens of the healthy eye is transparent and light can pass through without effort. In case of cataract lens gets thicker and becomes cloudy. It is hard for the light to pass through it and vision is being blurred. Form and scope of the opacification of lens can differ. If opacification have established further from the centre of the lens, then you can sometimes leave the existence of cataract unnoticed. Cataract can be the cause of cloudy or blurred image. It can be compared to frozen or steamed window.

Glasses can help in the initial stage of cataract but surgical treatment is necessary when the loss of vision caused by the cataract encumbers normal everyday life. Removal of the opacificated lens is possible only through surgery.

During the surgery of the cataract the lens that has developed opacification is removed from the eye. It is replaced by the artificial intraocular lens or contact lenses, sometimes powerful glasses are used.

Local anaesthesia is usually used in the cataract surgery. Laser in the cataract removal surgery is not used.