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The
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This is a low power image of the length of the entire wall of the eye. There are three main layers. The most outer layer is the Sclera, (black arrows). This is the "white of the eye". It is composed of collegen fibers and protect the eye. Anteriorly it becomes clear and is known as the Cornea. The next layer in is the Uvea. It is the Vascular Layer of the eye. It has three parts: the Choroid, the Ciliary Body, and the Iris. In this picture the blue arrows are showing the Choroid Layer, which has a rich vascular bed to supply blood to the retina and also contains pigment. The innermost layer is the Retina (red arrows). This is where the actual photoreceptors are located which are responsible for sight. Black arrows - Sclera Blue arrows - Choroid Layer Red arrow - Retina This next image is the Anterior portion of the Sclera called the "Cornea". In this image it is colored, but that is from the stain, in reality it is transparent. The Anterior Border of the Cornea (blue arrows) has a specialized Outer Epithelium. Just below that is what is known as Bowmans Membrane. The bulk of the thickness of the cornea is made up of Parallel lamellae of Collagen fibers. At the very Posterior border of the Cornea is Descement's Membrane (red arrows). Blue arrow - Outer Epithelium of Cornea Red arrow - Descement's Membrane
Here is a closer view of the Outer Epithelium of the Cornea. Notice the characteristic Stratified Non-Keratinized NON PAPPILATED epithelium. Non-papilated because the outer most surface is completely Flat. This is to correctly bend the light on to the retina. At the left most tip of the blue arrow is Bowman's Membrane. While the rest of the blue arrow is pointing to the thickness or Stroma of collagen fibers of the thickness of the Cornea. Red arrow - Outer Epithelium (Non-pappilated) Blue arrow - Stroma of Cornea
This is a close up of the Posterior border of the Cornea called Descement's Membrane. This outer most layer of cells function to keep dehydrating the cornea to allow clear vision. If these cells stop functioning, than the vision will get cloudy. Blue arrow - Stroma of Cornea Red Arrow - Descement's Membrane
Here is a low power shot of some of the major parts of the eye. First we have the Lens, (blue arrow). The Black arrow is showing the beginning of the Cornea. The red arrow and green arrows are pointing to the 2 structures of the Uvea. The green arrow is pointing to the Cilliary Body, while the red arrows are pointing to the Iris. The space labeled A corresponds to the Posterior chamber which is Posterior to the Iris. The area labeled B is the Anterior Chamber. Blue arrow - Lens Red arrows - Iris Green arrow - Cilliary Body Black arrow - Cornea A - Posterior Chamber B - Anterior Chamber
This is a closer image of the Cilliary Body (red arrow). The cilliary body is made up of mainly smooth muscle cells and functions in accommodation which is necessary for close vision. It also functions to produce the Aqueous Humor. The blue arrow is pointing to the Ciliary Processes. There are two main parts to the Cilliary body, which are the Outer Pigmented layer, green arrow, and the Inner Non-pigmented layer (yellow arrow). Red arrow - Cilliary Body Blue arrow - Cilliary Process Green arrow - Outer Pigmented Layer of Cilliary Body Yellow arrow - Inner Non-pigmented Layer of Cilliary Body
This is a closer look at the part of the Iris. The iris has two muscles with in it, the Sphincter (constrictor pupillae), indicated by the red arrows, which is responsible for constricting the pupil. The 2-ND is the Dilator muscle which is not pictured but would be further to the left of the sphincter muscle, and it functions to dilate the pupil. The green arrows are pointing to the posterior surface of the Iris where is located the Pigmented epithelium of the Iris. This is responsible for giving the color to your eyes. Blue arrow - Lens Red arrow - Sphincter or Constrictor Pupillae Green arrow - Pigmented Epithelium of Iris (Post. Surface)
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Layers of the Eye
Cornea
Outer Epithelium
Descement's Membrane
Gross Structures of Eye
Ciliary Body and Processes
Iris (pigmented epithelium and Sphincter) |
