I don't think this is correct. Your eye muscles might get 'tired' but there's no reason for damage to the eye to occur in terms of vision. Our eyes have evolved to compensate for motion very well. There is a similar myth that reading in low light damages the eye.
You're more likely to have a problem with car sickness. This is thought to be caused by a conflict in stimulus signals between your eyes and ears. Your eyes, focused on a relatively static object a few inches away, are telling your brain that you're still. Your inner ear, however, is sensing the forward motion of the car.
The thinking is that the brain assumes that the conflict is caused by something you've eaten; in evolutionary terms eating poison berries (etc.) that caused disorientation would have happened a lot more often than travelling at 70mph. So the brain tries to induce vomiting by causing intense nausea.
This is why it is a good idea to look up every so often and look out the window, so your eyes 'agree' with your inner ear.
Read Here : http://www.nytimes.com/2008/07/15/science/15qna.html?_r=0