Short-sighted salmon are to benefit from research on the prevention of cataracts. A study published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology shows that the nutrient histidine, when added to the diet of farmed salmon, prevents cataracts. Histidine is present in blood meal, which was included in the diet of farmed salmon until the early 1990s, when it was removed in the wake of fears over bovine spongiform encephalopathy. This move coincided with a large increase in the incidence of cataracts among the fish, affecting farmers' profits. The research was led by Jeremy Rhodes of the University of East Anglia's Norwich Eye Research Group.