My mother worked as a nurse for some time, and she has told me on several occasions that if a vein isn't hit the first try that I should tell them to stop, then ask for someone who knows what they're doing.
I used to donate plasma when I was attending college, and for some time I had no problem; one needle stuck in, draw for 20-ish minutes, done. Then, on the very last time I went there, one of their phlebotomists started fishing (which later left me with a baseball-sized bruise on the inside of my elbow). I told her to quit and get someone who can find a vein, and even though she looked pretty pissed off, the older lady she summoned found a vein on the first try in the other arm and the rest of the visit proceeded without incident.
What these glasses seem to be addressing is unqualified or under-trained people sticking needles into me. If I see someone approaching me wearing a pair of these things, I'm going to fold my arm back up and ask them to find someone who knows what they're doing.