To understand cataract, one has to visualize that an eye behaves like a camera with a transparent lens focusing light on the reel of the eye i.e. retina. The picture so formed on the retina is then sent to the brain via a nerve to complete the process of seeing. When this lens starts becoming opaque or white, the problem is labeled cataract. So when the lens is partially opaque, it is called an immature cataract and some light can pass through to help perform some routine functions. However, when the opacity increases to engulf the entire lens, vision is totally cut off and the cataract is called mature.

There is a painless progressive diminution of vision. Initially some help is achieved by changing the spectacle number, but in advance cases the spectacles also prove to be ineffective.

There is a painless gradual decrease in vision. Early cataract is associated with difficulty in reading in normal light conditions, and extra illumination is required. Excessive glare and reduced sharpness can make night driving difficult. Some experience a rapid changes in the number / power of glasses. In advanced cases there is complete loss of sight and pupil becomes pearly white in colour. 

Currently the best accepted technique to remove cataract the world over is through Phaco-emulsification. A small 2.8 mm incision is placed in the eye and a hollow Phaco needle is introduced through the opening. On giving energy through the tip of the Phaco needle, the cataract lens gets dissolved and is sucked out through this needle. An artificial lens called a foldable Intra-ocular lens is now injected through this small opening. Once inside the eye, it opens up and serves to replace the original lens. Since the eye opening is very small and designed in a special manner, it self seals and no sutures are required. Hence this procedure is also popularly known as ‘Stitchless’ cataract surgery.

The main advantages of Phaco are that a person has a good vision the very next day and may resume routine activities also the very next day. Stitches and related problems are things of the past. A person may now accomplish routine activities without spectacles, however a little spectacle correction may be required for fine focusing for distance and near.

The lens which is placed in the eye is of a fixed power. The power of the lens for a particular eye is calculated with the help of an eye ultrasound. After surgery, routine distance activities can be carried out without glasses. For reading, glasses would be required

Yes. These are called multifocal intra-ocular lens and give good vision without glasses for distance and reading. However in certain eye condition, a need for using a little spectacle correction may be felt for very fine work.

A multi-focal lens like the Tecnis from AMO (USA) and Restor from Alcon (USA) has several concentric rings of prisms. Each ring splits the light into two components, therefore, nearly 50% of the light is focused for distance and 50% for near. When the distance object is in focus, the near is out of focus and vise versa. Thus the person is able to see both distance and near objects clearly.

It is easier and safer to operate on an immature cataract by Phaco. As the cataract matures, it tends to become harder requiring more Phaco energy to do the same job. Beyond a certain limit, excess energy may cause harm to the eye.

Foldable (soft) lens has a diameter of 6.0 mm and is made of either Silicon or Soft Acrylic. It can be injected through a needle into the eye through the 2.8 mm opening made for the surgery. the lens unfolds automatically to take its position. Non-foldable (hard) lens has a diameter of 5.5 mm. A 2.8 mm incision has to be enlarged to 5.5 mm to introduce this lens. However the incision still remains self-sealing and requires no sutures, but it may induce some curvature changes in the eye.

The Blood Pressure (BP) and Blood Sugar should be in control. E C G and a medical checkup may be required in some cases.