Very interesting read by the folks at RED: Human Eyesight & 4K Viewing.
Higher resolution enables closer seating and detail resolving.
I had read similar articles in the past regarding the transition from standard definition (SD) TV to high definition (HD) TV.
As SD screens grew larger, the best viewing position was further and further away from the TV. HDTV changed that due to higher resolution – the best viewing position became much closer than with SD. Whereas the best viewpoint for SDTV may have been from across the room, the optimal viewing point for HDTV might be 7 to 10 feet from the screen (depending on the screen size).
Similarly with 4K TV – you may see more detail when sitting up close.
A problem with moving closer, though, is that for most adults over age 40-45, near vision is lost and reading glasses are required due to changes in the aging eye. All my life I had 20:20 (perfect) vision but with the onset of age, I eventually required reading glasses. To watch our HDTV from 7-10 feet away, I need to wear a +1.00 reading glass, which is so weak an adjustment that most drug stores do not carry these – I order them from Amazon.com.
This eyesight issue explains why, in past viewing tests, so many viewers are unable to notice a difference in 1280 x 720p versus 1920 x 1080i or 1080p. Many viewers may eventually buy 4k TVs but truthfully, many will not notice much difference in image quality because of their eyesight issues and lack of appropriate “reading” glasses for viewing the TV.