As an aside, this reminds of the prime example of "people are so stupid you can't even imagine": I checked some epilepsy forum when Avatar came out because I suspected it's dangerous and yes, people said it is not advisable and some got auras and some even seizures from the movie so I decided 3D movies are not for me. Not everyone though -- there was someone who posted "yeah, I saw the warnings here and went to see Avatar 3D and got a seizure" and I am like "you can't be real".
Edit: to whoever downvotes this, I had seizures when I was 20 years old. Despite numerous examinations including sleep deprived EKG, CT, MRI they never found out what causes them. So if you are downvoting this because I sound like we do not know what causes seizures then you are either ignorant (because we indeed do not know and I am the damned walking example) or have knowledge I really badly need. If the latter then please share links to new neuro research which will help me and my neurologist to decide whether I need to stay on medication or not. I would be glad to stop after two decades.
Each of your eyes gets a half of the light available to them both before and after.