Points to consider. Benchmark may be a poor choice of words, I don't know. Our company already has a service for hearing loss on an annual basis. Hearing probably changes some as we get older, but does loss of hearing have same affect on performance in a welding shop as sight does. Virtually everyones eyes get worse with age or abuse. Face it, AWS does not care if you can't hear a cannon going off next to you, but they do care if you can see the warts on a fleas butt. My main objective is to bring vision exams in-house mainly for inspection personnel. Charts cheap, vision plates cost more but there online alternatives. Like I said above, I am not trying to replace an optometrist screening as far as diseases or problems, just verify for our own purposes that people who do inspections can indeed see at an industry accepted level (Snellan 20/40 in at least 1 eye, Jaegar 2 in at least 1 eye, with or without correction and color blindness screening if applicable).
My case for testing welders also is to reduce or eliminate the excuse of "I did not see that porosity or undercut, etc." I know they are always going to use that excuse, but if they knew management knew they could see then they would have less of an excuse for leaving minor discontinuities for QC inspectors to find. It all goes to placing responsibility on the floor personnel for their own performance.
As far as the adequate lighting and other requirements, that is what I was curious to see if anyone had any guidelines for administering the exam. I have been going to optometrists for 20 years for vision screenings ($45 a pop even if employer does pay for it). They usually just hand you the Jaegar card and ask you to read line XXX. They show you a Snellan Chart at 20' and see how low down on chart you can read. They show you Ishihara plates and you tell them the numbers you see. No unusual lighting as I remember. I see no extensive special training required to administer that evaluation. The gentleman (ASNT Level III in everything) who recently did my vision exam for ASNT VT transitioning operates his business out of his home. Ambient lighting only but he asked me to read lines backwards and did more than the optometrist ever did to verify if I could see, not just memorize a chart before the exam. Just looking for general guidelines to make it somewhat legitimate. Guess I could just go to Walmart and ask their vision specialist.