It is bad to put two contacts in one case. If you put two contacts in one case, the amount of bacteria will double while the amount of clean agents of the solution in the case does not change. So it is hard for the contacts to be disinfected completely. If you wear them after this, the health of your eyes may be threatened by the bacteria. Putting the two contacts in one case may mix them up and you will end up with wearing the lenses wrongly. This will make your vision blurred. In some cases, the two contacts will stick to each other tightly. If separated by force, the lenses will be torn apart. Sometimes, the bacteria or viruses that lead to eye infection on one lens will be passed to the other if you store them in the same case, and thus make both eyes infected. Above all, you should not do that.