There is soon to be another health warning message on cigarette packets urging people to give up the habit - blindness.

Whilst we have been aware for years that smoking can clog up the blood vessels, including those of the eyes, new evidence now shows that smoking significantly increases the chance of the two commonest causes of blindness in the elderly-cataracts and degeneration of the macula (retina).

The largest study ever published on the subject has shown conclusively that smoking increases two-fold the chance of age related macular degeneration, the commonest cause of blindness in the West and a disease leading to an irreversible loss of the central vision making such tasks as reading and recognizing faces difficult or impossible.

Another large study from India has confirmed many previous studies on the subject that the chance of developing a cataract (an opacification of the eye’s natural lens) is much higher in smokers.

And by the way, smoking is a very common cause of chronically red eyes, and wrinkling of the facial skin.

Still, despite all the health warnings, we know that if we want to persuade a smoker to give up, nothing is more effective than increasing the price.