Yes, I also noticed this in myself, unfortunately. As the commentator above already indicated, it is very important to choose a 4-color deck - this will allow you to not look at the screen so much (and it’s just much more convenient, does anyone else play with a 2-color lol?). Personally, I also turn on the blue filter built into Windows and use “artificial tears” to moisturize my eyes to avoid discomfort and dryness.
At 68 years old I did have a problem with distinguishing Hearts from Diamonds and Clubs from Spades, and it was getting a problem when I though I had made a flush but in reality I hadn't. So I changed the Deck to 4 colours On-line and the problem was not a problem any more.
Relief came when I had an Eye test and it was found I had Cataracts in both eyes but Laser surgery cured that. So now I can play with both a regular Deck or 4 colour deck.