An omega-3 fatty acid found in fish -- DHA -- prevented age-related vision loss in laboratory tests, researchers in Canada found. Yves Sauve and his team at University of Alberta Faculty of Medicine and Dentistry discovered laboratory models fed DHA did not accumulate a toxic molecule at the back of the eyes. The toxin normally builds up in the retina with age and causes vision loss, Sauve said. \"This discovery could result in a very broad therapeutic use,\" Sauve said in a statement. \"In normal aging, this toxin increases two-fold as we age. But in lab tests, there was no increase in this toxin whatsoever. This has never been demonstrated before -- that supplementing the diet with DHA could make this kind of difference.\" Sauve\'s team recently started another study, looking at people who have age-related macular degeneration, a condition that results in the loss of central vision and is the main cause of blindness in those age 50 and older. The team said it wanted to determine whether participants with certain genetic markers will respond better to increasing amounts of DHA in their diet. The findings were published in the journal Investigative Ophthalmology & Visual Science.