Phone and TV don't have high nits to make anyone blind but surely decrease eyesight/cause strain over the period due to prolonged exposure. Try using your phone at peak brightness in a dark look for a prolonged period.
Uh what, phones these days are easily capable of over 1200-1300 nits. Also, why would I watch my phone at peak brightness in dark.
What you're saying is that distance from a screen affects eyesight which is straight-up wrong. Also, brightness doesn't cause myopia. myopia is caused by repeatedly straining your eye muscles which adjust your lens. It has more to do with your food and genetics.
High brightness can cause retina damage, which won't be fixed with spectacles. However, a 55" TV from 5.5 feet will look exactly the same brightness as 75" screen from 7.5 feet. At the same nits/cdm^-2, 75" TV will also generate proportionally more light output.
Why waste on a 55" TV then get a 24" monitor and sit at 2-3 FT. As per your logic same experience
It's not the same experience because you can't lay back from a PC monitor. But for gaming, a PC monitor is good enough. That's why the LG CX 48" is selling so much despite being the same price as the 55".
Size doesn't matter for a gaming screen that much.
Lastly, what are you doing in this group if you are not at all interested in a 75" TV?
I am interested in it, but as a hall TV as you can't move the sofa and multiple people watch it. We are discussing gaming, in which size doesn't matter.
If I was getting a TV for gaming, 75" TV is pure waste of money. You can just sit closer to the TV/monitor.
Distance from screen and brightness are definitely going to be factors for longevity of eyesight and the quality. Distance to screen will govern the focal length which will govern how much your eye muscles have to work to give you a clear picture.
Your eye muscles won't have any difference focusing 5 v/s 7 feet (0.2D v/s 0.142D). It's only that at very short distances they get strained and lead to myopia. I'm talking about 20-30 cm here.
Brightness is self evident, generally closer you sit to the screen higher exposure to brightness your eyes will have.
And a 55" TV from 5.5 feet is going to look exactly as bright as 75" from 7.5 feet if they have the same brightness output. They'll fill in the same field of view and are exactly the same brightness. The 75" is further away, but since it's bigger it generates proportionally more light output.