It seems that to do Bikram Yoga with contact lens is OK as it is not fierce. But it's not true. It is not OK to do Bikram Yoga with contacts. Bikram yoga is taken under the room temperature of 38â„ƒ-40â„ƒ, which is higher than average temperature and human's normal body temperature. Under that condition, the body will evaporate some water and the eyes will be comparatively dry, so that wearing contact lenses will no be comfortable. On the other hand, contacts lenses are directly touching cornea and relevant to optic nerve. When doing yoga, there are some moves that you have to stand upside down. At the time of doing these moves, the blood will flow to you face and have effect on optic nerves. In case of wearing contacts, the blood will be pressed by lenses and the pressure will be transit to the nerve. That will be harmful. Staring is also one of the moves of yoga. When you wear contacts, it will impact you staring and focusing. So that, don't wear contacts while do Bikram Yoga.
Generally speaking, you had better not wear your contact lenses while hot yoga, but if you do enough preparation, then you can do it. The most important is that you should take the eyes drops with you so that you can put some in your eyes when your eyes are dry; when you feel your eyes are dry. Besides, you should blink your eyes frequently so that your natural tears can spill out to moisten your eyes. If your eyes are tired while bikram yoga, you should look bright distance.
I suggest you not to wear contact lenses when doing bikram yoga because the high temperature may stimulate the bacterium invisible activities which may let the eyes get infected. In addition, you may sweat during the bikram yoga which may flow into your eyes. This may get the eye feel pain because of the acidity inner the sweat. If you don't want your eyes to get infected, you'd better not wear it during the bikram yoga.