What Is The Temporary Slight Green Tint In My Vision That Last A Few Seconds At A Time?

Hello! Only the last month I ve woken up with a green tint in my vision that only lasts a few seconds. 27 year old male and perfectly healthy as far as I know. I have great vision and even with the green tint phenomenon starting, its still clear as ever. No unnatural blurriness or spots. Any idea why?