You can wear contact lenses when you got hay fever, it won't be harmful, however, you'd better not. Because the wearing may make you feel more discomfort. It's suffering if you wear contact lenses when you are already not good.
You need to take some pills then sleep well, take off the contact lenses for one or two days before you fully recover.
Usually, it is not comfortable for you to wear your contact lenses when you have hay fever. Since you can really struggle with your contact lenses, your eyes will mist up, itch like crazy, red, swollen and some other allergies are also often. What's more, contact lenses should not be in hot, dry or dusty environments, while day fever affects daytime contact lenses because pollen gets trapped under the lenses and irritates the eye making it itchy and you want to rub them, thus in return making your symptoms of hay fever worse.
However, there is a new alternative to daytime contact lenses which does not involve switching, so you may go to find this kind of lenses to wear when you have hay fever.And the best contact lenses for hay fever are overnight lenses because you don't have to wear them during the day. Specifically, overnight contact lenses gently reshape the eye when you are sleeping, so it can correct the way light enters the eye and focuses on the retina so that you can see without them. Try this kind of lenses! That's really useful and helpful!
Well, of course not. You should not wear contact lenses if you suffer hay fever, it will just increase the risk of getting eye infection. First, you should know that when you have a cold which is caused by the virus, it may cause hay fever. And then your eye immune system can be weak, and then the virus will invade into your eyes, leading to eye infection. Of course, at this time, if wear contact lenses, which can be irritants, it will just make your situation become worse. In some cases, your eyes will turn to red and bloodshot, itchy too. For your situation, you should eat a diet rich in fresh fruits and vegetables, which provide lots of antioxidants, which may help boost your immune system, especially vitamins A and C. in this way, I think it can do a help to your eyes. Anyway, just be careful about it.