Yes, this is very common.
Most people are righthanded. People are used to use the left part of their body, so they tend to use the right eye more. The more the right eye is used, the higher risk of vision reduce problem may occur. While some people are lefthanded, they are more used to the left side. So their left eyes are likely to be weaker.
I guess you must be a lefthander, so your right eye has a better vision than your left eye.
Well, from what you said, I think one of your eyes is better than the other in terms of vision and sight, thus, visual ability in the darkness would be different, that is natural and of course reasonable. So you must try to protect your eyes from getting worse and get some eye drops to help. Most importantly, try to make proper use of eyes and take care of them.
Usually speaking, two eyes' vision may be similar which you could hardly feel the difference. However your situation is a little abnormal. Maybe your eyes get short sighted, one with higher prescription than the other. You'd better have the good rest for the eyes now and go to see the doctor to find the real reason for this situation.