I was playing in a mixed 7.0 USTA match over the weekend that had a funny little incident. The female player introduced herself and happily stated that she is blind as a bat and can't see the ball on line calls so she plays everything. I smiled and said "that's fine." She was a pretty darn good little player and it was a fun match. However, on one shot I had a nice hard volley to the back corner that was clearly in and I had a perfect view of it as well as 20/10 vision. She called it out and saw I was a little put off, but I never argue calls and just let it go. She thought I was agitated and commented that she clearly saw it out and her partner had no opinion. I just said it wasn't a big deal at all and smiled. A few points later I hit a similar shot that she called in. She stated she thought it was out but was giving it to us to make up for her bad call.
I just thought it was funny how she stated she was blind and couldn't see line calls but was adamant on one important point in the set.
I know some people around here would have thrown down the gloves at this point.