If they are snails You can get a yo yo loach they eat snails. I have 2 in my 55 community tank and they have kept the #'s down. Your not the only ones who's eyes are going. The only way I can see little print is hold it arm lengh away or futher to read it. My husband thinks I'm strange. I will sit in front of my aquariums with that magnyfying glass from Stapes looking at my fish and baby shrimps so I can see them better. I told Aunt Kymmie about them and she got a magnifyer also. Those tiny what ever and the tiny snails you can see all over the sand in my tanks. It also helps to spot problems on fish when they get sick.
eileen, I am seriously going to have to go look for one of those. I would like it just to be able to see more detail in the fish tank. As far as checking out the fish closer, mine move too fast. Looking back, I should have gotten slower swimming fish, not the "speedy fish" of the freshwater world. lol