Lens (anatomy)
The crystalline lens is a transparent, biconvex structure in the eye. With the cornea it helps to refract light to be focused on the retina. The lens changes shape. This changes the focal distance of the eye so that it can focus on objects at various distances. This adjustment of the lens is called accommodation. It is similar to the focusing of a photographic camera when it focuses its lenses. The lens is flatter on the inside.
| Lens | |
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| Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. | |
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| Schematic diagram of the human eye. | |
| Latin | lens crystallin |
The lens is also called the aquula (Latin, a little stream, dim. of aqua, water) or crystalline lens. In humans, the refractive power of the lens in its natural environment is approximately 18 dioptres. This is about one-third of the eye's total power.
Lens (anatomy) Media
3D lens model from sheep with parts labeled and images of cells from different parts overlayed
Sheep eye lens para-formaldehyde fixed front view. Small lenses are about 1cm in diameter. Small bumps at edge are remnants of suspensory ligaments
Sheep lens fixed side view. Note the largest lens has damaged capsule and iris attached
Microscope image of lens cell types and capsule
Sheep lens capsule removed. Decapsulation leads to a nearly formless blob.
A foot on a mouse lens capsule suspensory ligament forming part of the Zonule of Zinn
Lens showing feet attached to the eye lens capsule with smaller feet embedded in the capsule
Cellular and supercellular structure in the mouse lens. Photos at increasing depth: A-Epithelium B-Broadening fiber ends C-Fiber ends lock together D-F- Voids G-Vacuoles I-Sutures
Similar to a human, this is a lens forming in a chicken eye
3D reconstruction of lens in a living 20 year old human male focusing from 0 dioptres (infinity) to 4.85 dioptres (26mm) side & back views
