1,5 half day of regular office use of Pixel 3aXL i.e. used the phone checking regularly my emails, calendar use, phone calls etc. I have upgraded the phone to Android 10 (it came with 9), so i am not sure if i can return the phone to Amazon now.
When i set the brightness at 75% , colour boosted and night light on, the phone caused me mild eye strain and headache after 2 hours of office use. However i did not experience neck cramps, or severe headache or nausea like i get with most iphones and other android phones i have tested. So this is a good thing for me.
I also tested it after installing the oled saver app. I think the app makes the display easier on the eyes, , so i am keeping this app.
I summary, it maybe the best option to replace my dying phone (Vodafone phone with Android 5.1 from 2016) since i have not found any better phone yet. All the phones i have tested (Huawei P30 Lite, Sony Xperia XA and XZ, all iphones, Huawei Mate, Samsung A40/70) create much more and immediate adverse symptoms.
Also since i used it only 1,5 days i may be able to get more accustomed to it. I did the same with my current phone when i first got it.