Uhmmm, maybe it is my background as a photonics scientist, but what is the « signal » the eye detects that is contracting the muscle? As far as I am aware, only the rods and cones in the retina can transform the light into a signal that can be used by the brain for reactive functions (eye closing or opening, blinking, averting light etc.) if the sensor is not sensitive (for example in the infrared wavelengt range), then the eye does not react (this is why IR is potentiall’y dangerous since there is no blinking reflex).
by the same token if the light is modulated faster than the response time of the photosensitive cells, the light is effectively invisible and there is no signal that the brain can use… hence my question
But is the light coming from the OLED display modulating fast enough and in a steady pattern to not be picked up by the rods and cones in the eye? There are also dithering, auto brightness and refresh rate changes to consider along with the ambient light around us. Our eyes must be rapidly reacting to all the sensory information. I don't understand the science, I only know the debilitating effects caused to my eyes and brain when using these devices. This is something that I have never experienced before using the iPhone X and subsequent phones + iPads.
Who measured and decided the modulation speed that the human eye can see and not see? Genuine question as I've seen many people state that our eyes should not be able to see fast PWM. Colours, smells, taste and the perception of the world are all experienced differently. Clearly, as you state to have a background in Photonics, you could share and educate us with valuable information to bring a greater understanding of what might be the route cause.
Full disclosure, I have short-sighted vision with an astigmatism. I wear corrective contact lenses that give me what I feel is perfect vision, allowing me to use a desktop computer all day for work and an OLED TV in the evening with no issues. I work as a graphic designer and scrutinise the smallest of details (and see all minor errors). It's possible my corrective lenses or glasses are adding a factor in how my eyes receive light from these iPhones and tablets.
My most recent experience: Using the newer iPhones with PWM and 120hz refresh rates causes a bizarre swimming feeling when looking away from them. The screens move so smoothly it almost feels unnatural making everything around me look slow with a slight tunnel effect for a few seconds, then I feel the strain in my eye muscles - the early warning to stop looking. The light coming off these screens feels strong and bright like a torch is being shined onto my eyes, this is not something I experience with LCD iPhones. Having tried to preserve before has led to an almighty migraine that has wiped me out for a whole day. Some of the iPhones, like the standard 12 and 13, have had less instant negative effects (I was able to use them for several days) but the eye fatigue would build and a headache would form.
I now find I cannot use the iPad Pros as these also have PMW, and even though the 11” M1 version is reported as not having PWM, I still get eye fatigue. So I have to conclude that dithering is playing a part or maybe the light-emitting technology and/or display drivers? Something most certainly is not right with the displays for me and I'm not alone, the voices on the internet have been getting louder over recent years.
www.androidcentral.com
www.epey.co.uk
