Missing figures/tables
It is a daily ritual...wake up, eat, shower, contacts, class. I do this every morning, however I have never stopped to think, "Why?"
No, not "Why am I going to class so early?" but "Why do I need these contacts?" With this project I will attempt to explain the basics of vision and corrective lenses, as I, myself, finally learn the reason for sticking my finger in my eye every morning.
Basic Eye Anatomy
The cornea is responsible for protecting the eye and for refracting incoming light rays.
The pupil is merely an opening that allows light to enter into the eye. Its black color is attributed to the fact that light is not able to exit the eye through the pupil.
The iris acts to control the size of the pupil. In bright light, the iris is dilated in such a way as to reduce the size of the pupil and limit the amount of entering light. In dim light, the iris adjusts its size as to maximize the size of the pupil and increase the amount of incoming light.
The crystalline lens is a fibrous, jelly-like material that serves to fine tune the vision process by adjusting its shape and therefore the focal length of the system.
The ciliary muscles relax and contract to change the shape of the lens.
The retina contains rods and cones which detect the intensity and frequency of incoming light and, in turn, send nerve impulses to the brain.
Behind the Eye
The four main components of the eye that are responsible for producing an image are the cornea, lens, ciliary muscles and retina. Incoming light rays first encounter the cornea. The bulging shape of the cornea causes it to refract light similar to a convex lens. Because of the great difference in optical density between the air and the corneal material and because of the shape of the cornea, most of the refraction to incoming light rays takes place here. Light rays then pass through the pupil, and then onto the lens. A small amount of additional refraction takes place here as the light rays are "fine tuned" so that they focus on the retina.
This is a representation of the eye's lens system. This eye has no eye condition, such as nearsightedness or farsightedness, and the lens is drawn in its relaxed position. The light rays are focused appropriately on the retina. The thickness of the cornea is 0.449 mm, the distance from the cornea to the lens is 2.
The pupil is where light can enter the eye. The iris is in control of the amount of light that actually goes through. The light reaches the lens, which alters the shape of it so the eye can focus on it. Light reaches the retina, which consists of cones and rods. Colors are saw differently based on their implied meanings, which to various psychological functions. The cones are responsible for color. The color red would have such an effect on people’s perception of others based on their production of affect, behavior and cognition. A sociocultural theorist would explain this effect by indicating that the associations with the color red are normal. When a student sees a plethora of red marks on their paper, they automatically think they failed the assignment. Biological theorist would best explain this theory by saying the color red helps them survive or reproduce. A man may be attracted to a woman more because she is wearing red. This attractiveness could cause him to find his mate and eventually reproduce. A behavioral theorist would explain this effect by saying the color red provokes pleasure and avoids pain. A person can associate red with romance and
An inspection of the modern animal phyla will reveal that eyes are just as diverse as they are complex. Some organisms like the rag worm have pigmented cup eyes while other like he box jellyfish have two lens eyes and two pairs of pigment pit eyes. To account for the diversity in eye structure, we must first examine the eye ‘prototype’, the original structure that was acted upon by evolution. The simplest organ that can be considered an eye is composed of a single photoreceptor cell and a single pigment cell, without any lens or other refractive body (Arendt, 2003). Such organs are know as eyespots, and...
There are rods and cones in the back of your eye that are in the retina, these are connected to the bipolar cells and a set of nerves called the interneurons. The first step is the bipolar cells to hook up with the ganglion cells that lead out of the eye. From there the axons and the ganglion cells join with the optic nerve carrying messages from the eye to the brain. Next the axons of all of the ganglion cells join to form the optic nerve. This is taken to a place in the eye on the retina called the blind spot. The blind spot is a place where there are no receptor cells, so when light hits it there will be no imagine seen. After the nerves are made into fiber they leave the eye and enter the brain where they split to either side of the brain at the optic chiasm. The nerve fibers from the
When light pass through your lens and hits the back of your eye (retina) where you can have rods and cones that type of cells are responsible for peripheral vision. Because of all this research I know now why I can only see to a certain point when I look with the side of my eyes. Its cause your eyes need to practice more to see more like the color to a certain point and shape. You practice you will learn that your eyes will see more and long as you keep your eyes healthy.
A lens is an optical device that transmits or refracts light. Eyeglass lenses are glass or plastic items that are placed inside eyewear frames in order to correct the wearer’s vision. More than 80 percent of all eyeglasses worn today are plastic lenses. The glass lenses were popular in the 1945 until the plastic lens was introduced in 1952. Convex and concave lenses are known as spherical lenses. Convex lenses were the first lenses used to correct vision problems. They are used to correct hyperopia (farsighted vision). These lenses are thicker in the middle than at the edges. Concave lenses are used to correct nearsightedness. This is a condition that makes people see things that are close to them but struggle to see things far away. Concave lenses are curved inward like the inside of a spoon.
First of all, it has three layers; the Sclera, Choroid and Retina. The muscles attached to the Sclera control eye movements (“Anatomy and function of the eye,” 2011). Other parts of the eye, iris, cornea, pupil, lens and optic nerve play essential roles in the function of sight. The iris is the colored area of the eye. It is the muscle that regulates the size of the pupil which allows light to enter. The cornea, the clear layer over the front of the eye, is responsible for refracting that light. The lens is behind the pupil. It helps to focus, but the cornea that does the most to focus the light. There is also the aqueous humor, which is another clear layer is made of gel that nourishes the cornea. The retina is the tissue containing cells that convert light into color, sending them to the optic nerve where the brain receives the information and interprets the image ("How We See",
Eye lens: Found behind the pupil the retina focuses light and changes shape to enable you to see things fa...
[6] Vera-Diaz A F, Doble N. Intech Journals [Internet]. The human eye and adaptive optics; 2012 January 20 [cited 2014 May 20]; [about 6 lines]. Available from: http://www.intechopen.com/books/topics-in-adaptive-optics/the-need-for-adaptive-optics-in-the-human-eye
and the iris which is the colored part of the eye, it regulates the amount of light
reflexes can be obtain. Placing a light close to the eyes and observed the pupils
Understanding how our eyes work can be a really interesting thing. Many people don’t realize vision actually begins when light rays are reflected off an object that then enters the eye through the cornea. The cornea is a transparent bulge, in the front of our eyes that allows us to begin refraction. The cornea is one of the most important things in our eyes that allow us to see the things we do. After the reflected light rays enter the cornea, they then p...
In these photos, I am going to explain both the anatomy and the physics behind the human eye and what allows us to see the way we do. The physics portion of the eye will apply mainly to the lens of the aqueous humor. These portions of the eye are going to be responsible for refracting light into the eye and focusing it on the fovea centralis. I am going to briefly discuss the way the eye absorbs excess light so that it is not reflected out of the eye. Finally, I will discuss abnormalities of the eye and how that affects the way light is refracted.
One sub-system under the sensory system is the visual system; the main sense organs of this are the eyes. The eye is the sensory organ that allows us to detect light from external stimuli. When a light ray is detected, the eye converts these rays into electrical signals that can be sent to the brain in order to process the information and giv...
The cornea and the crystalline lens act together to focus the light on the retina and provide vision following a specific procedure as shown in figures 2 and 3. It begins when light enters the eye through the cornea which is the transparent, prolate, front refractive surface of the eye with 43 Dioptric power. After that, the light is refracted to pass through the pupil where its amount is regulated by the constriction or dilation of the sphincter or dilator muscles of the iris, respectively. Then the light will pass through the second refractive surface of the eye which is the crystalline lens with 20 Diopters of power and having a transparent biconvex shape, the light is refracted onto the retina. (Garrity, 2015) (Vail,
This reflected light passes through the lens and falls on to the retina of the eye. Here, the light induces nerve impulses that travel through the optic nerve to the brain, where it makes an image of the object, and then that image is passed on to muscles and glands.The eye is well protected. It lies within a bony socket of the skull. The eyelids guard it in front. They blink an average of once every six seconds. This washes the eye with the salty secretion from the tear, or lachrymal, glands.