Are these symptoms of dyslexia?

Recently, I've noticed something odd about my grandfather: he can read proficiently. Sometimes.

He never could do that, in the past; he stared at writing with a rather confused expression, and it would take him many minutes to read a short sentence.

However, with some things, he can read much faster. I thought this may have been memorization, but now it seems as though, oddly, it's about the font. He has trouble with black-on-white, but red-on-white or green-on-white is much easier for him.

I read somewhere that dyslexcs sometimes have an easier time with certain styles of writing. Is it possible my grandfather is dyslexic?

He could just have a weird color perception combined with nothing else.

Sounds like Irlen Syndrome, which is a visual processing disorder that underlies some cases of dyslexia.

I have Irlen Syndrome. This sounds very much like it to me as well. Sounds like colored overlays would help with the reading. I'd recommend going to the Irlen Institute. It has stuff like symptoms, self tests, links to professionals, and tools like the overlays. Figuring out I had It was a huge help to me with, stuff like reading, depth perception, fluorescent lights, and head aches.

It's hard to say for sure what his lexical issue is from that bare-bones description. There are a few shape- and layout-based processing issues that can underpin various dyslexic and dysgraphic conditions, as well. <shrugs>

Age-related changes could also mean other issues. <_< You can both win and lose at the ageing game as synapses run to keep up with neighbouring neurons giving up the ghost. <shrugs> Irony: you stumble along a pathway that previously never fired up, because the one you're used to can't work any more thanks to age (that may include thanks to sight problems having nothing to do with actual processing and everything to do with going long sighted or slowly blind).

Is there something about three year old topics that makes them necro fodder?