I would never let anyone represent you in a "screening." Why you might ask, so a person sits in this box, and reads the letters on the 20/20 line or a wall chart 20 feet away. An associate (i.e. a Walmart associate or whomever doing the screening because the manager says so) says oh you see 20/20 you don't need a new Rx or an eye exam. But, is this person licensed to diagnose this customer/potential patient by just having them read a 20/20 line. Can they look in and see glaucoma or a melanoma. Just remember this person is under your license for whatever is said. You've worked too hard to obtain it.
Oh and I hate when a parent will say, "Well, the school nurse said (another brother or sister that's not getting an exam today) that they are not having trouble reading or seeing distance. Again a person not in a position to give medical advice. You really have to set yourself apart, and educate the parent at this point of why the child needs a real eye exam. Especially its even easier if they have insurance and a ten dollar co-pay.
I'm in total favor of a national manditory pediatric exam by at least the age of 5 or 6.
just my 2 cents