I have heard that called "starbursting" where the pin has rays coming out of it or a wider halo around it. I had the problem when I changed to a 6X lens and #2 clarifier. Yellow and red fibers were unbearable - I couldn't even focus on my target because of the starburst effect. Green was better, especially if I kept some blue painter's masking tape to tone down the fiber in bright sun. Blue fiber was best, but you have to be careful that you don't wind up with the opposite problem - the blue can fade into lighter colored targets and may not give good visibility in lower light situations.