The Lenses and Refraction ClipArt gallery offers 37 illustrations of light changing direction as it passes through media with different refractive indices.

"In <em>optics</em>, a deviation in the rays of light when unequally refracted by a lens or reflected by a mirror, so that they do not converge and meet in a point or focus, but separate, forming an indistinct image of the object, or an indistinct image with prismatically colored edges."-Wright, 1902

Aberration

"In optics, a deviation in the rays of light when unequally refracted by a lens or reflected…

A cut of a gemstone. A brilliant cut stone has fifty-eight facets.

Brilliant Cut

A cut of a gemstone. A brilliant cut stone has fifty-eight facets.

"Because of their greater refrangibility, the focus of the violet rays is nearer the lens than the focus of the red rays, as illustrated. If the screen is as near the lens as the focus marked v, the outer fringe is red. If the screen is as far from the lens as the focus marked r, the outer fringe is violet. This difference in the deviation of differently colored rays is called chormatic aberration." -Avery 1895

Chromatic Aberration

"Because of their greater refrangibility, the focus of the violet rays is nearer the lens than the focus…

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup, with a shilling on the bottom, in such a position that the side of the cup will just hide the piece of money from the eye. Then let another person fill the cup with water, keeping the eye in the same position as before. As the water is poured in, the shilling will be come visible, appearing to rise with the water. The effect of the water is to bend the ray of light coming from the shilling, so as to make it meet the eye below the point where it otherwise would. Thus the eye could not see the shilling in the direction of c, since the line, of vision is towards a, and c is hidden by the side of the cup. But the refraction of the water bends the way downwards, producing the same effect as though the object had been raised upwards, and hence it becomes visible." &mdash;Comstock, 1850

Cup and Shilling

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup,…

This illustration shows a Double Brilliant (sometimes called Lisbon) cut gem.

Double Brilliant Cut

This illustration shows a Double Brilliant (sometimes called Lisbon) cut gem.

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more than the blue; and as the objective gives a large blue and small red image, the two cancel one another and a colourless image is produced." &mdash;Encyclopaedia Britannica, 1910

Huyegenian Eyepiece Diagram Showing Lens Refraction

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more…

"If the real image produced by the objective coincides with the collective lens, only the inclination of the principal rays is altered. The lens nearer to the eye is distant from it about its focal length. The eye&mdash;lens converts diverging pencils into parallels. Both lenses together form the exit pupil of the objective behind the eye&mdash;lens." &mdash;Encyclopaedia Britannica, 1910

Ramsden Eyepiece Lens Refraction Diagram

"If the real image produced by the objective coincides with the collective lens, only the inclination…

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to overcome the dispersive effect for some of the colors without overcoming the converging effect." -Avery 1895

Achromatic Lens

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to…

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident ray." -Avery 1895

Refraction of Light through Bi Convex Lens

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident…

"When the object is at a long distance from the lens, the image formed is smaller than the object, and inverted." -Foster, 1921

Convex Lens

"When the object is at a long distance from the lens, the image formed is smaller than the object, and…

"The shape of the double convex lens, d, c, is that of two plano-convex lenses, placed with their plane surfaces in contact, and consequently the focal distance of this lens is nearly the centre of the sphere of which one of its surfaces is a part." -Comstock 1850

Double Convex Lens

"The shape of the double convex lens, d, c, is that of two plano-convex lenses, placed with their plane…

"Double convex lenses are used in the eyeglasses for old people, becoming more spherical according to the age of the person or the magnifing power required." -Comstock 1850

Double Convex Lens Magnifing an Arrow

"Double convex lenses are used in the eyeglasses for old people, becoming more spherical according to…

"The double convex lens may be described as the part common to two spheres that intersect each other. The centers of the limiting spherical surfaces, as c and C, are the centers of curvature. The straight line, XY, passing through the centers of curvature is the principal axis of the lens." -Avery 1895

Double Convex Lens

"The double convex lens may be described as the part common to two spheres that intersect each other.…

"BA is the ray of light passing through a rare medium (as, for instance, air); and upon its entrance into a denser medium (as, for instance, water) the ray will be deflected from the direction of its path BA, and will take the course AE. If the line CD is perpendicular to the dividing surface between the two media, then BAC is the angle of incidence and DAE is the angle of refraction." -Waldo, 1896

Atmospheric Optics

"BA is the ray of light passing through a rare medium (as, for instance, air); and upon its entrance…

The figure "illustrates the bending of the solar rays entering the atmosphere. When the sun is below the horizon, at C, it would be invisible at A, on account of the curvature of the earth, if there were no atmosphere; but the solar rays entering the atmosphere near the point B are refracted so that they reach A, and the sun appears to be at D, though really at C below the horizon, either in the morning or in the evening. So that, in the polar regions, the sun is visible while it is in reality below the horizon, and is thus seen earlier and later during the time of polar sunlight." -Waldo, 1896

Atmospheric Optics

The figure "illustrates the bending of the solar rays entering the atmosphere. When the sun is below…

The halo phenomena is illustrated in this diagram.

Atmospheric Optics

The halo phenomena is illustrated in this diagram.

Double Porro prism systems are used in small optical telescopes to re-orient an inverted image, and especially in many binoculars where they both erect the image and provide a longer, folded distance between the objective lenses and the eyepieces.

Porro Prism

Double Porro prism systems are used in small optical telescopes to re-orient an inverted image, and…

"A prism is a transparent body with two refraction surfaces that lie in intersecting planes. The angle formed by these planes is called the refracting angle." -Avery 1895

Prism

"A prism is a transparent body with two refraction surfaces that lie in intersecting planes. The angle…

"The following simple experiment illustrates the effect of refraction:&mdash;Place a silver coin, m, at the bottom of the basin. The rays, i i, proceeding to the eye from the silver surface, render the coin visible. The point a, the eye, is then moved farther bck, so that the edge of the basin obstructs the direct rays, and of course the coin is no longer seen. If an attendant carefully pours water into the basin, so that the object is not moved, it will presently, as the water rises in the basin, become again visible. This arises from the refraction of the rays by the water, the image, indeed, appearing at n instead of at m." &mdash;Wells, 1857

Refraction

"The following simple experiment illustrates the effect of refraction:—Place a silver coin, m,…

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction." &mdash;Croft 1917

Refraction of Light through Glass

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction."…

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the end B in the direction of the refracted ray, and it appears at D instead of where it really is." -Foster, 1921

Refraction

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the…

"Since air is a rarer medium and water is denser, as ray A passes into the water, it is refracted to C. Also note that as ray B leaves the water, it is refracted to D as it enters the air." &mdash;Quackenbos 1859

Refraction Between Mediums

"Since air is a rarer medium and water is denser, as ray A passes into the water, it is refracted to…

"Although a ray of light will pass in a straight line, when not interrupted, yet when it passes obliquely from one transparent body into another, of a different density, it leaves its linear direction, and is bent, or refracted more or less, out of its former course." -Comstock 1850

Refraction of Light

"Although a ray of light will pass in a straight line, when not interrupted, yet when it passes obliquely…

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular direction." -Comstock 1850

Refraction, air, water, glass

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular…

"Showing how an object is refracted through a biconvex lens." -Avery 1895

Object Refracted through Biconvex Lens

"Showing how an object is refracted through a biconvex lens." -Avery 1895

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two surfaces are equal and contrary in direction. The direction after passing through the plate is parallel to the direction before entereing the plate; the rays merely suffer lateral aberration." -Avery 1895

Refraction by Plates

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two…

"The prism will deflect the red and orange, and form a reddish colored image at n. The violet, indigo, blue, green and yellow light, not caught by the prism, will unite at f to form a greenish image. When the prism is removed, the reddish light that fell at n, and the greenish light that fell at f, unite to form white light." -Avery 1895

Refraction of Complimentary Colors

"The prism will deflect the red and orange, and form a reddish colored image at n. The violet, indigo,…

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the molecules of the glass, and impart some of their motion to those molecules' i.e., a part of the light is absorbed. When a beam of light, as represented by ABC moves forward in the air, the wave-front, MN, continues parallel to itself and moves forward in a straight line. As the wave front advances, A strikes the glass first, and is retarted, the retardation of B and C later change the direction of the rays." -Avery 1895

Explanation of Refraction

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the…

"Illustration depicting the refraction by the eye." -Comstock 1850

Refraction by the Eye

"Illustration depicting the refraction by the eye." -Comstock 1850

"Let the medium b be glass, and the medium c, water. The ray a, as it falls upon the medium b, is refracted towards the perpendicular line e d; but when it enters the water, whose refractive power is less than that of glass, it is not bent so near the perpendicular as before, and hence it is refracted from, instead of towards the perpendicular line, and approaches the originial direction of the ray a g, when passing through the air." -Comstock 1850

Refraction, glass and water

"Let the medium b be glass, and the medium c, water. The ray a, as it falls upon the medium b, is refracted…

"LA represents a ray of light propagated in air, falling obliquely upon the surface of the water at A, and deviated by the water from AE to AK." -Avery 1895

Refraction of Light Between Air and Water

"LA represents a ray of light propagated in air, falling obliquely upon the surface of the water at…

"If the ray passes in the opposite direction, i.e., from water into air, the process is the reverse of that just indicated. Let KA represent the incident ray." -Avery 1895

Refraction of Light Between Water and Air

"If the ray passes in the opposite direction, i.e., from water into air, the process is the reverse…

"If the coin were to be observed in an empty pan and then watched as the pan was filled with water, the image of the coin would be refracted to position N." &mdash;Quackenbos 1859

Refraction as seen by the Human Eye

"If the coin were to be observed in an empty pan and then watched as the pan was filled with water,…

"Suppose the rod a, to be set with one half of its length below the surface of the water and the other half above it. The eye being placed in an oblique direction will see the lower end apparently at the point o, while the real termination of the rod would be at n; the refraction will therefore make the rod appear shorter by the distance from o to n, or one-fourth shorter than the part below the water really is." -Comstock 1850

Refraction, water

"Suppose the rod a, to be set with one half of its length below the surface of the water and the other…

A rose cut is a cut of gemstone. In this cut, the upper surface is shaped into triangular facets of nearly equal size throughout.

Rose Cut

A rose cut is a cut of gemstone. In this cut, the upper surface is shaped into triangular facets of…

A split cut is a cut of gemstone. It is similar to a trap cut.

Split Cut

A split cut is a cut of gemstone. It is similar to a trap cut.

A Trap Cut is a cut of gemstone. Emeralds are commonly cut this way.

Trap Cut

A Trap Cut is a cut of gemstone. Emeralds are commonly cut this way.