My astigmatism (if I don't wear my glasses) makes the dot look like a slash, angled down from left to right. With glasses, it's a dot.
My red-dot sight is an old Tasco. I have a newer one for a different air pistol and it's a 4 MOA dot. Too big, didn't like it, so the sight sits on a shelf. Not an expensive one, as I think it was only about $55.00.