Some time ago I've been told that push-ups on your fingers (instead on fists) can affect eye-sight. The explanation was not clear (something about a lot of nerves in fingertips and pressure on them).
According to some teachers of Chinese systems, the fingertips should not be trained at all, as in Chinese medicine over-stimulation of the fingertips can affect one's eyesight.
Blade forum - thread about doing push-ups on fingertips
Doing push-ups on tips of fingers stresses and damages meridian pathways (this is oriental medicine) and may damage health and generally speaking,eyes.
Martial Talk - thread about finger push-ups
Is it at least partly true ?