Ok, I think you are very worried about your eye health. So it is true that one of your eyes could be drier than the other. Since infections could happen on one of our eyes. It makes sense for you to deal with it by getting medical treatment and take care of your eyes by getting healthy foods and vitamin intake. Dry eyes could also be found on one of your eyes. So just take actions.
It is normal. You should take no worries about that. Everyone has a dominate eye. If the dominate eye overuses and gets tired, then the situation which your left eye is drier than the other one happen. So after a long-time work , you'd better take a few minutes to have a rest.
Yes, it is normal. That's because most people are righthanded and some are lefthanded. We all have preference to use one side of our body which we have been used to. As a result, this side is used more and exhausted more. So it is with your eyes. You use your left eyes more and your left eye is overloaded. Then your left eye is dryer than your right eye. By the way, why do you say left eyes and right eyes? How many eyes do you have then?