Well, yes, caffeine can lead to dilated pupils, so you should not eat too much caffeine. As we know that caffeine is a stimulant and causes a release of adrenaline. And then the adrenaline can make us to be 'fight or flight' stressful situations. Of course, one of these effects, dilated pupils can occur. By the way, you should know that high blood pressure, hyperventilation, muscle tensions are the most common ones which can be related to dilated pupils. So you can search more information about it.
Yes, it could cause that. It is widely known that caffeine is a stimulant and causes a release of adrenaline. It is the hormone that prepares us for flight or fight in stressful situations, and it has a number of effects on the body. One of the obvious effects is a dilated pupil.
Well, it seems that you woud like to drink coffee on a regular basis, and frankly speaking, so do I. Anyway, you should know that coffee is not that healthy which means that it could give rise to some side effects of your body. Most of the time, these side effects are not obvious in a short time. And indeed much too coffee contains a lot of hormones and toxics which could harm your body and cause dilated pupils, just like smoking weeds. Anyway, drink less and try to take more exercises.