The FAA considers VLOS "With vision that is unaided by any device other than corrective lenses"So is visual line of sight (VLOS) the range that the human eye can see or the length at which you could technically "see" the drone if you had binoculars or something?
It’s the unaided distance the pilot or spotter pilot if applicable - while in direct communication with the pilot - can clearly see the copter in order to see and avoid a possible collision with another aircraft. It also serves nicely when trying to avoid trees, buildings, people, anything the copter could hit. There is no standard distance as everyone’s eyes are different. Eye glasses would not count as aided, but binoculars would.
The FAA considers VLOS "With vision that is unaided by any device other than corrective lenses"