I've called around to about a dozen optometrists in a 100 mile radius with no luck. I haven't tried any schools or an ophthalmologist though. I'm in denial about having to do a SODA evaluation, it's my last resort because one mistake could result in a permanent restriction.
And the colors of your particular display may have helped a lot more than resolution. When I was in the photo biz, we calibrated our monitors all the time. There's a vast difference otherwise (look at the monitors displayed at your local MicroCenter, or the TVs at Best Buy) that my affect your ability to pass a test.... I passed an ishihara test on my phone today, but again the sharp color on a display helps a lot. ...
I took the ishihara very informally at the AME's office. He wasn't particularly interested in helping me through it. Pretty much every optometrist has the ishihara book, so maybe I need to just take another crack at it. Newer printing is MUCH easier for me than dull older print. Same goes for sectionals vs. sectionals on Foreflight with the more vivid color. I ordered an Ishihara book from an optometry supply house today, I'll practice with it a bit and see.
I've been practicing on colors a lot lately. I have a PPL but I really want to go commercial MEL so I can do a little 135 stuff part time or maybe even go into business flying. It's been my dream my whole life, that's why I'm so timid about it.
What I've found is I can actually see colors better than I give myself credit for. I found that for years I had given up and threw my hands up when really with just a little effort and some differentiation technique I could figure things out. I noticed I can pick out colors if I go with my gut at first glance rather than staring. I passed an ishihara test on my phone today, but again the sharp color on a display helps a lot.
I got my SODA at a towered airport by identifying the light gun signals. I failed the ishihara, also the one at the FSDO where you look into a black box. light guns was my last resort - don't have to worry any more. I did this in the '90's
...just about all are LED, now, with dead batteries and dropped on floor (ruining ability of the controller to aim the thing right at you.....)I wonder if any of the light guns have switched from incandescent to LED, changing the difficulty of differentiating.