An employer has a special duty towards a one-eyed man (Paris v. Stepney Borough Council, 1951) but does not have a special duty to a man with normal sight because employment could normally continue with good monocular vision. Clearly, a man with very defective vision in one eye needs the same consideration as a one-eyed man so we examined the level of visual acuity which should alert the employer to giving a man special consideration.
Two consultant oculists examined a chemist with Leber's syndrome and found 6/24 vision in each eye. One consultant advised taking greater care of the man's eyes because if one eye was lost, or became further damaged, he would have difficulty in continuing laboratory work. His colleague advised that the loss to the man would be of binocular vision and a no greater proportional loss than to the man with normal sight.
Loss of binocular vision is considered greater in a man with poor eyesight because his visual acuity might, as in the present case, go from 6/18 using both eyes to 6/24 using one. We consider that wherever an employee's (corrected) sight is 6/18 or less in either eye then his case should be given special consideration which may then indicate the need for the provision of extra eye protection.