Yellow forelock--a new neuro-ophthalmological sign.

We examined a middle-aged man with a prominent yellow forelock who complained of loss of vision in both eyes. He smoked his pipe avidly and drank a little Bourbon whisky daily. The nicotine content of the forelock (21.7 ng/mg) was 10 times that of the hair on his occiput (2.23 ng/mg). A yellow forelock when associated with isolated painless visual loss suggests tobacco amblyopia.