Wiktionary
naked-eye
a. Pertaining to the unaided eye, as in unaided sight.
Usage examples of "naked-eye".
There were other galaxies by the hundreds of millions in their line of sight, but only a few dozen of them were naked-eye objects, and those only pale, tiny smudges of firefly light.
I once saw a bamboo shoot growing at naked-eye speeds: nano is directed, and faster than that.