I'm suggesting it should mention your eyes instead of hands. When playing, your eyes are blinking much less than ever before. This has to do with the fact that you must concentrate a lot during playing, especially if the beatmap is long and intense. This can lead to some serious consequences. Cookiezi quit mainly because he got xerophthalmia (very dry eyes)
Eat carrots and give your eyes a break.
Another common thing to have is periorbital dark circles under your eyes. Which I often have after using my computer.
Can I blame my excessive computer usage for my glasses?