Noah Webster
Visual
VIS'UAL, adjective s as z. [Latin visus.]
Pertaining to sight; used in sight; serving as the instrument of seeing; as the visual nerve.
The air, no where so clear, sharpen'd his visual ray.
Visual point, in perspective, a point in the horizontal line, in which all the ocular rays unite.
Visual rays, lines of light, imagined to come from the object to the eye.