I use a pair of contact lenses for a month and then get them changed... the last pair I had, I wore them for more than 30 days, and I was getting some red eyes and blurry vision... until I got an infection in one of the eyes on Tuesday... It was so red an swollen and couldn't see anything bright... I contacted a pharmacist and she gave me some eye drops and a antibiotic... It's getting better everyday although it is still a bit red...
What could have caused the infection and how can I prevent it from happening again? When should I use contact lenses again?...

Thank You!