Photos 1 and 2: Fresh batches of young males emerged; they have light green eyes. Eyes darken with age (starting at the top), ultimately becoming all black. Photos 3 and 4: Taken a few days earlier and show older males (eyes already distinctly darker). Photo 5 shows entire nest with males of various ages. Photos 6, 7 and 8 are close-ups taken two days later. Majority has black eyes now.
Note: This is the same nest as here: https://www.inaturalist.org/observations/30613885