My brother has a bright red squiggly line coming from the bottom of his eye towards his pupil (not yet touching). eye isnt irritated, otherwise normal?

Blood vessel : Your description sounds like a conjunctival blood vessel that is a normal constituent of the eyes outer moist coat. They tend to become more visible with aging and ocular irritations, like dryness, allergies, infections and exposures. Unless this is a brand new suddenly developing or worsening observance, I would suggest monitoring for change. Artificial tears are a soothing solution for many.