It is obviously abnormal that your eyes sting when you wear contact lenses, you need to find the causes and try to avoid it. First, your eyes may be sensitive to your solution, or just your eyes may be dry. Thus you can try using some moisturizing eye drops. Second, it can be caused by dirt, so you need to take a little more time cleaning your contacts when you take them off each night and change the solution you store them and give them a good rinse-off with your solution saline. At last, if you can not adjust to your present lenses, you can just to to the store and buy another fit you well. That may help you!
There are lots of reasons can lead to the sting of your eyes when you wear contact lenses. You eyes probably get infections if you didn't wear the contact lenses with a wrong method. Maybe your contact lenses was broken, or even they are out of date.
Check out the contact lenses to see if they are in good condition combine with the validity. Then follow the wearing direction, keep your hands clean. If there is nothing wrong with the contact lenses and your wearing method, the problem may be your eyes.
Use artificial tears at first, then see a doctor if there's no improvement.