WE have long known that fish oil positively affects our eyes and vision. High amounts of omega-3 - the active component of fish oil - have been measured in the retina and may be essential to eye health.

Now we have the scientific proof - from one of the world's leading medical institutions. We know that it helps prevent a condition called age-related macular degeneration (AMD).

This is a disease linked to ageing that gradually destroys sharp, central vision. Central vision is needed for seeing objects clearly and is especially necessary for tasks such as reading and driving. AMD affects the macula, the part of the eye that allows you to see fine detail. It causes no pain.

In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses quickly and may lead to a loss of vision in both eyes. AMD is a leading cause of vision loss in Americans 60 years of age and older.

Blindness

The disease is the leading cause of blindness among older Americans of European descent and the number of individuals with advanced AMD is expected to rise by 50 per cent by the next decade.

The macula is located in the centre of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. It then sends these impulses, or nerve signals, to the brain.

Researchers from Wilmer Eye Institute at Johns Hopkins University report in this month's issue of the journal Ophthalmology that fish that contain abundant amounts of the omega-3 fatty acids EPA and DHA can protect against the development of AMD. The new research led by Sheila K. West, PhD, evaluated data from 2,391 participants between the ages of 65 and 84 in Maryland. Dietary questionnaire responses were analysed based on the type and amount of fish and shellfish consumed weekly. Photographs taken upon enrolment were evaluated for the presence and grade of macular degeneration.