Question

if humans are opaque then why when we put light on our finger it glows? isnt that translucent

Answer 1

Skin appears flesh-toned when light is shining on it, but it's actually quite transparent (the reason why people get a blue-tinge when their blood doesn't oxidise, for example). When you flash a flashlight through your skin, you see through the transparent skin into what's inside, and your fingers are full of (for the senstive people in the audience) red stuff.

Hope that answers your question. :)