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Optometry

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Template:Optometry is a branch of medical science and the study of the eye’s defects and the process in which corrective lenses are prescribed. Optometry deals with the basic diseases and problems within the eye that can be corrected with lenses while an Optometrist is the actual career that correlates with optometry, but optometry itself deals with the broad study and technologies of how the eye can be corrected. [1]

History of Optometry

Optometry has progressed immensely over the years from primitive forms of glasses to lasers that can now reshape the cornea. The history of optometry and the implementation of corrective lenses began with Roger Bacon. He was the first person to recognize that lenses could help those who cannot see effectively. Not long after Bacon realized the importance of lenses, the first pair of spectacles were created. In 1684, Johannes Kepler became the first person to understand and describe the retina, and put practical uses toward corrective lenses. [2]


Optometry in the United States looks completely different than it did in the beginning of the twentieth century. In that time almost anyone could practice optometry and issue corrective lenses, even without the knowledge of the function of the eye. Optometry was not viewed as a medical profession, but as a craft to build corrective lenses. One would suppose that the tradesmen would have needed knowledge of the function of the eye to accurately construct a sufficient eyeglass to fit the needs of the wearer. However,the makers of the eyeglass did not understand the diseases and problems within the eye. Each person who requires corrective lenses has different eyes and vision needs. Some of the tradesmen would set up testing areas where people could test several different strengths of eyeglass and pick the lenses that they thought fit their needs. The case is completely opposite in today’s society. In modern day optometry, the optometrist prescribes the eyeglasses that they think will improve vision and not just satisfy the problem for a short term solution. The lack of knowledge of optometry in the past allowed some people to take advantage of others. They would scam the people because there were very few regulations in the field of optometry. In modern times, optometry has completely evolved into a professional medical field with regulations. [3]

Anatomy of the Eye

The eye is a very complex structure that has many different parts to produce an image. The brain also plays an important role in what we see. The eyes allow light in and send the message to the brain, and the brain interprets the images that we see. The retina sends electronic messages that project the image upside down, and the brain turns around the image so we can see normally. The optic nerves carries electric impulses to the brain so the brain can flip the image. Light is very important in eyesight. Light enters the eye through the cornea, and the retina converts the light to a message that the brain can receive. The pupils and the iris affect how much light travels to the retina. In the dark, the pupils become very large in order to let as much light in as possible, so we can see even through darkness. The pupils do the opposite in the sunlight so we can maintain clear eyesight. The components of the eye are the choroid, cornea, fovea, iris, lens, macula, optic nerve, pupil, retina, sclera, and the vitreous humor. Each component preforms a specific function so that we can see. [4]

Vision Problems and Diseases

An eye with Glaucoma

There are many disorders and conditions with the eye including:

Astigmatism

One of the most common vision problems is astigmatism. Astigmatism causes blurriness in the eyes and is caused when light does not pass correctly to the retina. Currently, no one knows how a person can get astigmatism. However, optometrists do know that astigmatism can be passed along through genetics and be present in the child. The severity of astigmatism can vary as the child grows older. Many people have astigmatism, varying from extreme blurriness to a slight blurriness that cannot be noticed. A person only needs treatment for astigmatism when it becomes a discomfort and hindrance. To fix astigmatism, optometrists either prescribe contacts or glasses. The corrective lenses change the way light passes through the eye and into the retina. With the development of technology, laser surgery can also treat several types of astigmatism. [5]

Glaucoma

Glaucoma is when an eye disease or condition severely damages optic nerves. The destruction of the optic nerves leads to a decrease or total loss of vision. The most common forms of glaucoma arises when pressure builds up in the eye and is called primary open-angle glaucoma. People with primary open-angle glaucoma do not even know they have it until vision has decreased. This form of glaucoma can be dangerous to the eyes because there are few warning signs and it occurs over a steady pace instead of a rapid change in vision. There is no known cure for glaucoma. Instead, glaucoma can be controlled only if it is found in early stages. Once glaucoma has taken vision away, the vision lost cannot be recovered through any technologies in present day medicine. [6]

Myopia

The common name for myopia is nearsightedness. Myopia is very common and is the condition when distant objects are blurred but close objects are not. Generally, myopia becomes present in a person when they are a child, but recent studies have shown that adults can also contract myopia. This is when someone works with objects close to them all the time and causes stress on the eyes. Objects looked blurry because the light does not properly travel through the eye. Usually, the cornea causes the light to incorrectly pass to the retina. There are several procedures to reshape the cornea so light can properly reach the retina. Laser surgeries as well as rigid contacts can help form the cornea into the right shape. Optometrist will usually prescribe corrective lenses to help improve myopia. [7]

Hyperopia

Hyperopia is also known as farsightedness. People with hyperopia are able to see objects in the distance, but cannot focus on close objects well. Hyperopia can be harder to detect than myopia and can take some further testing. Optometrists prescribe corrective lenses to improve hyperopia. [8]

Technology and Tests

Phoropter

A phoropter used in optometry tests.

Phoropters are very common in the field of optometry. Phoropters are a very useful technology that serves a very important purpose. They allow for doctors to easily prescribe the amount of prescription a patient needs in their corrective lenses. The doctors can switch tests lenses in and out and ask the patient which lenses helps them see a chart on the opposite wall. The phoropter gives influence to the patient in letting them let the doctor know what is helping them see better. There are some other technologies that can automatically test and prescribe prescriptions without the input from the patient. [9]

Autorefractor

A man using an autorefractor to test the eyesight of a girl.

Autorefractors are machines that automatically determine the prescription needed for the patient’s eyes. The autorefractor measures and determines where the focus point is in the retina, where the eye perceives images. The autorefractor is very accurate and provide an alternative for the phoropter, especially for children who might not be able to best describe what test lenses helps them see the best. The autorefractor can expedite the checkup process and quickly make a judgment of the patient’s vision needs. Doctors will sometimes use both the autorefractor and the phoropter in order to prescribe the best overall solution for the patient. [10]

Puffer Test

The puffer test assesses the amount of pressure in the eye. The puffer test is a simple examination that tests for glaucoma. The actual machine is called the slit lamp and puffs a blow of air into the patient’s eye. From the previous section describing glaucoma, testing for glaucoma can be very beneficial to catch it in an early stage before it causes great damage to the eye. The puffer test is easy to perform as well sit through. The test does not take very long, but the benefits of the tests are great. An easy and simple test could prevent a major eye problem. [11]

Video

References

  1. An Overview of Optometry. Xavier University of Louisiana. Web. November 6, 2013 (Accessed). Author Unknown.
  2. History of Optometry. American Optometric Association. Web. October 23, 2013 (Accessed). Author Unknown.
  3. History of Berkeley Optometry—Part I Berkeley Optometry. Web. November 6, 2013 (Accessed). Author Unknown.
  4. The Eye. University of Michigan Kellogg Eye Center. Web. October 23, 2013 (Accessed). Author Unknown.
  5. Astigmatism. American Optometric Association. Web. October 23, 2013 (Accessed). Author Unknown.
  6. Glaucoma. American Optometric Association. Web. October 23, 2013 (Accessed). Author Unknown.
  7. Myopia (Nearsightedness). American Optometric Association. Web. October 23, 2013 (Accessed). Author Unknown.
  8. Hyperopia (Farsightedness). American Optometric Association. Web. October 23, 2013 (Accessed). Author Unknown.
  9. What is a: Phoropter. EyeGlass Guide. Web. November 6, 2013 (Accessed). Author Unknown.
  10. What is an: Autorefractor. Eyeglass Guide. Web. November 6, 2013 (Accessed). Author Unknown.
  11. is an: Puffer Test. Eyeglass Guide. Web. November 6, 2013 (Accessed). Author Unknown.