I think it depends on what you mean by better vision.
I think video games help with your response time, your eyes ability to pick up smaller details as your always searching in video games for tiny clues or targets.
I think however that prolonged play in the dark and up close can damage your eyes tho, especially over long periods of time.
In good lighting tho at a reasonable distance I don't think it hurts your eyes more than reading a book or staring at anything for the same time period. I think all of the "it'll make you go blind" crap was started as a way to scare children from playing too much at a time.