Colour blind cricketers and snowballs.

OBJECTIVE--To determine whether colour blindness affects batting in professional cricketers. DESIGN--Comparison of batting averages of colour blind cricketers and those with normal vision. SETTING--Players on 18 first class county cricket teams. SUBJECTS--280 of 306 players were tested. MAIN OUTCOME MEASURES--Results of Isihara colour blindness tests. RESULTS--Batting average for the colour blind group (12 players) was slightly lower than for players with normal vision (20.88 v 26.31). There was no difference in the number of batsmen and bowlers affected. Batting averages before and after the introduction of the white ball into Sunday League cricket did not differ significantly. CONCLUSIONS--That batting performance is not significantly impaired by colour blindness suggests that to some extent these players are self selected. Routine testing of cricketers for colour blindness is not recommended.