A 24-year-old walks into a Tuesday evening clinic having been hit in the left eye by a squash ball two days ago, under a pair of goggles that had ridden up his forehead. He was fine to drive home afterwards and did not think much of it. What brought him in is that the eye has stayed dim — the way he puts it, the colour has been drained out of that side — and two days on it has not budged. He has never needed spectacles and has no other health problems.