Oddly enough for me at nighttime is when I see none of the color gradient on my Oasis. Its totally even in bed. I use it at light at 8 and a side lamp. Then I have no cones, no shift, nothing. But if I sit in the living room at night, different lighting there on the sofa, I notice the cones and shift if I turn the light on too high. Too high being over 11 on light. Since my light never goes above 11, day or night, I just never see the things I know are there. Its why I kept it. If its not there in my reading situation, it doesn't exist for me.
I just wish I could actually read in bed like others. I fall asleep to fast and can't remember many pages I read the next morning.