Your cleaning regimen could be the culprit. Lenses that are covered with mucky deposits or left in your eyes too long could irritate the cornea, leading to itching, infection -- even, in rare cases, blindness. Try doing these:

1. Cook the case: Boil for 5 minutes every month to kill bacteria; air-dry.
   
2. Don't mix it up: Use one type of cleaner for each pair. Chemicals can get stuck inside soft lenses, and competing brands could cross-react and irritate your eyes.
   
3. No swapping: Resist the urge to borrow your buddy's novelty lenses for the big game -- or you may end up sharing more than team spirit.