"Left eye closed, right eye looking through the notch of the rear sight so as to perceive the object aimed at it." — Moss, 1914

Aim

"Left eye closed, right eye looking through the notch of the rear sight so as to perceive the object…

"Each rear-rank man aims through the interval to the right of his file leader and leans slightly forward to advance the muzzle of his piece beyond the front rank." — Moss, 1914

Aim

"Each rear-rank man aims through the interval to the right of his file leader and leans slightly forward…

The human eye. Labels: a, crystalline lens; b, retina; c, cornea; d, sclerotic; e, choroid; g, ciliary processes; h, vitreous humor; k, pupil; i, iris; o, optic nerve.

Eye

The human eye. Labels: a, crystalline lens; b, retina; c, cornea; d, sclerotic; e, choroid; g, ciliary…

A human eye, used for sight, pictured with an eyebrow.

Eye

A human eye, used for sight, pictured with an eyebrow.

The eye and its muscles. Labels: o, the nerve of sight; a, one of the muscles of the eye.

The Eye and its Muscles

The eye and its muscles. Labels: o, the nerve of sight; a, one of the muscles of the eye.

An illustration of a human eye.

Human Eye

An illustration of a human eye.

"The most essential parts of human vision are contained in the eyeball, a nearly spherical body, about an inch in diameter, and capable of being turned considerably in its socket by the action of various muscles." — Avery, 1895

Eyeball

"The most essential parts of human vision are contained in the eyeball, a nearly spherical body, about…

"The eye is moved about by six muscles. The back ends of these muscles are attached to the eye sockets. The front ends are attached to the ball of the eye." — Ritchie, 1918

Muscles of the eyes

"The eye is moved about by six muscles. The back ends of these muscles are attached to the eye sockets.…

"Gun. A, breech; B, barrel; C, band; D, breech-block; E, butt; F, butt- or heel-plate; G, front sight or bead; H, guard- or trigger-plate; I, guard-bow; K, hammer; L, lock; M, peep-sight; N, N, pipes; O, pistol-grip; P, rear sight; Q, receiver; R, side-screws or -nails; S, S, stock; T, tip; U, trigger; V, wiping-rod." -Whitney, 1911

Parts of the Gun

"Gun. A, breech; B, barrel; C, band; D, breech-block; E, butt; F, butt- or heel-plate; G, front sight…

"Diagram showing how the lens changes its form for near and far sight." — Tracy, 1888

Eye lens

"Diagram showing how the lens changes its form for near and far sight." — Tracy, 1888

"A poor man here is asking for relief, / The full-fed, portly man appears quite deaf; / He's humbly pleading - see the poor creature; / The big man before him grows still deafer; / Alas! how passing strange does this appear, / None are so deaf as those that will not hear. / Of those whose vision's dim, where'er they be, / None are so blind as those who will not see."—Barber, 1857

None so Deaf as Those That Won't Hear

"A poor man here is asking for relief, / The full-fed, portly man appears quite deaf; / He's humbly…

"To construct a sighting rest for the pistol take a piece of wood about ten inches long, one and a quarter inches wide, and nine sixteenths of a inch thick. Shape one end so that it will fit snugly in the middle of the pistol when the magazine has been removed. Screw or nail this stick to the top of a post or other object at such an angle that the pistol when placed on top of the stick will be approximately horizontal. A suitable sighting rest for the revolver may be easily improvised." — Moss, 1914

Pistol sighting rest

"To construct a sighting rest for the pistol take a piece of wood about ten inches long, one and a quarter…

A flattened shape of the globe of the eye causes farsightedness and an elongated shape of the globe of the eye causes nearsightedness. The diagram illustrates the position of the retina in these conditions. Labels: B, natural sight; G, farsightedness; C, nearsightedness.

The Position of the Retina in Near and Far Sight

A flattened shape of the globe of the eye causes farsightedness and an elongated shape of the globe…

A sight is an optical device used to assist aim by guiding the eye and aligning it with a weapon or other item to be pointed.

Rifle Sight

A sight is an optical device used to assist aim by guiding the eye and aligning it with a weapon or…

"To show how a shadow if a perpendicular object is to be projected on an inclined plane." -Benson, 1891

Shadow of a Perpendicular Object

"To show how a shadow if a perpendicular object is to be projected on an inclined plane." -Benson, 1891

In animals there are different types of sight. Some have what we call simple eyes. The simplest eyes are not capable of forming an image or picture of external objects. They only make the animal able to distinguish between light and darkness or shadow. This diagram shows the simple eye or a jellyfish.

Sense of Sight

In animals there are different types of sight. Some have what we call simple eyes. The simplest eyes…

"Take an empty pistol ammunition box or a similar well-made box, remove the top and cut notches in the ends to fit the rifle closely. Place the rifle in these notches with the trigger guard close to and outside one end." — Moss, 1914

Sighting rest for rifle

"Take an empty pistol ammunition box or a similar well-made box, remove the top and cut notches in the…

"A telescope is an instrument designed for the observation of distant objects, and consists essentially of an objective for the formation of an image of the object and of an eyepiece for magnifying this image." — Avery, 1895

Telescope

"A telescope is an instrument designed for the observation of distant objects, and consists essentially…

"The Galilean telescope has a double-concave eye-lens that intercepts the rays before they reach the focus of the objective." — Avery, 1895

Galilean telescope

"The Galilean telescope has a double-concave eye-lens that intercepts the rays before they reach the…

"The spy-glass or terrestrial telescope avoids the inversion of the image by the interposition of two double-convex lenses, m and n, between the objective and eyepiece. The rays diverging from the inverted image at I cross between m and n, and form an erect magnified, virtual image at ab." — Avery, 1895

Terrestrial telescope

"The spy-glass or terrestrial telescope avoids the inversion of the image by the interposition of two…

"Then Tobias taking of the gall of the fish, anointed his father's eyes. And he stayed about half an hour: and a white skin began to come out of his eyes, like the skin of an egg. And Tobias took hold of it, and drew it from his eyes, and immediately he recovered his sight. And they glorified God, both he and his wife and all that knew them." Tobit 11:13-16 DRA
<p>Following the instructions of the angel Raphael, Tobias applies the gall of a fish to his father's eyes and his sight is restored.

Tobias Anoints His Father's Eyes with the Gall of the Fish

"Then Tobias taking of the gall of the fish, anointed his father's eyes. And he stayed about half an…