Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Processes of visual perception
Processes of visual perception
Anatomy and physiology note of eyes
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: Processes of visual perception
Our eyes stand today as one of the most complex organs in our body today. How our eyes take in light and refine them into crystal-clear images has become one the most hotly-debated topics of today, as no one has ever completely studied and researched the eye. Therefore, my question was, “How does red eye occur and how does it apply to the two major factions of eye structure?” Due to extensive preliminary research, I have found out much about eye structures and how to perceive vision from another point of view. The general eye can be classified as two main builds: the simple eye and the compound eye. The simple eye, the one that we have, looks mainly like this:
In this diagram above, the main light-sensing organs are labeled. When light enters the eye, it must first pass through the cornea and the pupil, which is like a window in which light is filtered and floods in. Then, the light gets filtered once again by two walls called the iris, which detects color and sends these messages to the brain. The light continues to pass until it hits the retina or the lining on the back of they eye, which acts as a sort of screen on which to place the image. Here, nerve sensors take the image as impulses and send it to the brain.
Relating to my main question, I would like to talk about red eye, and eyeshine in general. Red eye appears in flash photographs in dimly lit areas, such as the aquarium or a movie theatre. This happens when the bright light in flash photographs illuminate our pupils like a light pouring in a room, allowing us to peer inside. The red color comes from blood vessels inside our pupil. For vertebrates such as dogs, cats, bats, and owls, a mirror-like gland called the tapetum lucidum coats the retina, which reflects ...
... middle of paper ...
... hole of the pupil. By investigating a rented piece of calcite, I could find how the compound eye structure could not work and how it cannot successfully reflect light at a direct angle.
In conclusion, my conclusion is that red eye only applies to eye structures with reflective surfaces, such as the simple eye. Compound eye structures are coned and have a layer of graphite, unable to reflect any light back but needing to absorb only direct light to produce a certain image.
Our lives sometimes depend on our eyes. Think of covering your eyes and walking across a busy street. By investigating red eye and how it applies to our lives today, we can use it to our fullest advantage. For example, eye doctors shine bright lights into our eyes to get a look inside without harming us. This type of research can lead to major improvements on laser surgery and safer eye habits.
Optometrists have accepted vision therapy, which is a medical treatment for optical muscle disabilities, as a feasible treatment used for eye related problems; claiming the treatment can strengthen vision and give the patient the opportunity to understand visuals quicker and clearer (Press). Vision therapy originated in the 1950s and over the past 25 years, has gained popularity, mainly because of new technological innovations in the field of treatment. Generally, vision therapy is prescribed as a measure mainly for people between the ages of 3 and 18. With the results from a comprehensive series of eye tests, the optometrist can work with the patient using special instruments—prisms, filters, occluders, and eye lenses—and strengthen the eye muscles, thus improving sight. According to optometrists in favor of vision therapy, these methods of treatment using these instruments function as safer routes to repair eye disabilities. Although vision therapy can yield favorable results, the practice as a treatment for innate eye disabilities has been in hot debate lately; as it can exceed $8000 and insurance companies do not cover the treatment. For decades, insurance companies have refused to accept vision therapy as a legitimate method for repairing eyesight (Boink). Concomitant with lack of insurance, the cost for a full treatment can exceed $8000, and doctors cannot guarantee a successful outcome. Recently, parents of children with eye related disabilities, such as amblyopia (lazy eye) and strabismus (cross-eye), and doctors have attempted to cooperate with public schools to allow families access to school-funded doctors to practice vision therapy. With a tight budget, most schools cannot afford to supply vision therapy, and a...
Heterochromia Iridis is the Greek term for “differently colored irises”. More popularly known as just heterochromia, as the term is described two different-colored eyes that are on the same being. Heterochromia is most commonly found in cats. Instead of calling the condition heterochromia, the term often used for cats is “odd-eyed”. Along with heterochromia, however it has been supposedly known to be linked to other disorders, such as deafness making odd-eyed cats can be more vulnerable to. While heterochromia is usually present when the disorder; deafness is found, heterochromia in cats does not stimulate hearing loss than normally would, because how the mutation develops doesn't contributed to the linked condition, the certain breeds who are more susceptible to heterochromia along with the other associated disorder, and one known condition (hearing loss) linked to cats with heterochromia.
My interest in the career of optometry stems from my first experience in the optometry office to receive my first pair of glasses when I was in middle school. I distinctly remember the moment when my optometrist slipped my new glasses over my eyes for the first time. Suddenly, everything in the room came into sharp, clear focus. I knew that the glasses would help me see the board in school, but I was astonished to find that I could see small details about the room, as it had never before occurred to me that I should have been able to see these details. I was also surprised that I was even able to see the expressions on the faces of people who were standing far away from me. It was one of the most incredible, freeing, and empowering moments of my life. As I walked out of the optometry office, I felt
Land, M.F.1965. Image formation by a concave reflector in the eye of the scallop, Pecten maximus. J. Physiol. (Lond.) 179: 138 153.
the eyes had densely packed lenses and may have served merely as a light sensitive
Many signs include a "white pupil," also known as leukocoria. Retinoblastoma can occur in either one or two eyes (Paul T. Finger, Pg. 1). This abnormal white pupillary reflex is sometimes referred to as a cat's eye reflex. Another sign of retinoblastoma is a crossed eye (Ambramson, Ch3). Leukocoria doesn't always end up as being retinoblastoma, it can even result in: congenital cataract, Toxocara canis, Coat's disease, and persistent hypertrophic primary vitreous (PHPV) (Finger, Pg.2). Retinoblastoma occurs when there's a mutation or deletion of the q14 band of chromosome 13 (Finger, Pg. 1). Symptoms can be painful if not treated quickly. Some include a red, painful eye, swelling of the surrounding eye, poor vision, dilated pupil, even extra fingers or toes, and retardation (Ambramson, Ch3).
The red spot is easily diagnosed with an ophthalmoscope by a physician. The red spot is found in the retinal area and appears the color red due to gangliosides residing in the retina’s ganglion cells. The cherry red spot is the only normal portion of the retina due to choroidal circulation being shown by the red in the foveal region. This is a direct result of the retinal ganglion cells being pushed aside to increase visual perception. The cherry red spot shows up in contrast the remainder of the retina. Due to the excess ganglioside storage, the retinal neurons are now distended. The below picture shows an example of the cherry red spot in a TSD
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.
the cornea and the sclera. The cornea is what covers the iris, and is the
Our senses are very important because they allow us to see, hear, smell, taste, and touch so we can experience the life around us. The eye is the most important sensory organ. It is the organ of vision, and it is very sensitive. Therefore, we should protect our eyes from diseases; such as, macular edema, cataract, macular dry enteration, and red eye. We have all experienced red eye at least once in our life, affecting one or both eyes. That makes us wondering, what is Red eye? What can cause it? And how can we treat the causes?. Red eye is a cardinal sign of ocular inflammation. It occurs when the vessels in the eye become swollen or irritated. Red eye occurs as a consequence of blepharitis, dry eye syndrome, or conjunctivitis (med scape,2012).
Visual perception and visual sensation are both interactive processes, although there is a significant difference between the two processes. Sensation is defined as the stimulation of sense organs Visual sensation is a physiological process which means that it is the same for everyone. We absorb energy such as electro magnetic energy (light) or sound waves by sensory organs such as eyes. This energy is then transduced into electro chemical energy by the cones and rods (receptor cells) in the retina. There are four main stages of sensation. Sensation involves detection of stimuli incoming from the surrounding world, registering of the stimulus by the receptor cells, transduction or changing of the stimulus energy to an electric nerve impulse, and then finally the transmission of that electrical impulse into the brain. Our brain then perceives what the information is. Hence perception is defined as the selection, organisation and interpretation of that sensory input.
According to Mayoclinic.org the definition of cataract is a clouding of the normally clear lens of your eye (July 2013). I would like to discuss with you the pathophysiology of this disorder, the causes of this issue as well as some of the effects it can have on you, and some treatment options for those you suffer from this internal eye disorder. A cataract affects the lens of the eye. The lens is generally clear in color, and it is elastic in nature. The lens is surrounded by a capsule like case and sits behind the iris inside the eye (“Cataracts” Linton 2012). When the lens of the eye becomes cloudy, blurred, or there seems to be a more dim vision which replaces the normal transparency, this is called a cataract (“Cataracts” Linton 2012).
Severe causes of red eye that can lead to visual loss include keratitis, iritis, and acute angle-closure glaucoma. These conditions require emergent referral to an eye specialist (ophthalmologist). Due to the importance of this condition, it is critical that patients understand its causes, symptoms, and treatment. By the end of this article, you will
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...
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.