Well, in my opinion, eye strain cannot cause sinus pain. So you do not need to worry about it too much. And generally speaking, eye strain can just lead to redness in your eyes. And also, watery eyes, dry eyes, and pink eyes can be possible. But on the other hand, there is no evidence which can show that eye strain can just cause sinus pain. And of course, for sinus pain, it is often caused by infection and allergies. So that is sinus infection occurs. To reduce eye strain, you need to make your eyes to have good rest and also, doing some eye exercises can be helpful.