The power of a LASER

1. The power of a LASER Written by Nilisa Crespo

2. What's the big deal? • Lasik eye surgery has been the new epidemic since contacts and glasses. Many see this as a remarkable discovery while others see it as a gateway to poor eyesight. How do we trust the power of a laser to cure poor eyesight and make it 20/20 vision? There are many risks as well as benefits. How do we take the plunge to something so risky? The eye is a complicated organ that requires an exact arrangement of components to function. If even one of these components is not exactly the correct shape, then light that falls on the eye will not be focused correctly. For centuries, people have relied on external lenses to alter the angle of the light entering the eye. Whether in glasses or contact lenses, they have proven invaluable in the correction of poor vision. While external lenses will remain popular for the future, advances in technology have made it possible for surgeons to alter the shape of the eye itself. This is a great advancement that has changed the many lives of individuals.

3. Glasses or Contacts? • For many years people struggle with the constant battle with glasses and contacts. Glasses have never been harmful to the naked eye. Instead they have been more of a hassle then a way to better eyesight. They are fashionable and are extremely safe. Unfortunately they are not for everyone. There are people who prefer contact lenses. Contact lenses are the easy solution to poor eyesight. They come in different colors and shades bringing a lot of individuality. Even though contact lenses are unique and easy to manage they do come with a lot of risks. For example in order to wear contacts you need solution. That solution may harm your eyes and there is an increased risk of corneal infections, scratches, and scrapes. This leaves many people with lasik eye surgery to turn to. Now…is it the clear choice to bad eyesight?

4. What is lasik eye surgery? • -Lasik eye surgery is a popular surgical approach used to correct vision in people who are nearsighted, farsighted, or have astigmatism. It is a procedure that permanently changes the shape of the cornea which is the clear covering of the front eye using an excimer laser. A knife called a microkertome is used to cut a flap in the cornea. A hinge is then left at one end of this flap. The flap is folded back revealing the stroma which is the middle section of the cornea. Pulses from a computer control laser vaporization and a portion of the stroma is replaced.

5. How the procedure works

6. Advantages of going under the knife… • There are many advantages to this procedure as well as disadvantages. Some of the advantages include: • It corrects vision. Around 80% of patients will have their desired vision after LASIK laser eye surgery. • This suregry involves very little pain. • Vision is corrected nearly immediately or by the next day after LASIK laser eye surgery. • Recovery is quick and usually no bandages or stitches are required after LASIK laser eye surgery. • Adjustments can be made years after LASIK laser eye surgery to further correct vision. • After having LASIK laser eye surgery, most patients no longer need corrective eyewear.

7. Disadvantages • Some of the disadvantages include: • Changes made to the cornea cannot be reversed after LASIK laser eye surgery. • Corrections can only be made by additional LASIK laser eye surgeries. • Surgery is expensive, costing $2,200 to $2,250 per eye; compared to the cost of glasses and contact lenses, the price is relatively good. • Problems may occur when the doctor cuts the flap, which can permanently affect vision. • Surgery can cause a loss of "best" vision with or without glasses at 1 year after surgery. Your best vision is the highest degree of vision that you achieved while wearing your contacts or eyeglasses. • During lasik eye surgery Some patients experience discomfort in the first 24-48 hours after surgery. • Infection and delayed healing • Seeing halos around images • Difficulty driving at night • Fluctuating vision • Dry eyes • Some patients lose vision. Some patients lose lines of vision on the vision chart that cannot be corrected with glasses, contact lenses, or surgery as a result of treatment.

8. Some patients lose vision. Some patients lose lines of vision on the vision chart that cannot be corrected with glasses, contact lenses, or surgery as a result of treatment. Some patients develop debilitating visual symptoms. Some patients develop glare, halos, and/or double vision that can seriously affect nighttime vision. Even with good vision on the vision chart, some patients do not see as well in situations of low contrast, such as at night or in fog, after treatment as compared to before treatment. You may be under treated or over treated. Only a certain percent of patients achieve 20/20 vision without glasses or contacts. You may require additional treatment, but additional treatment may not be possible. You may still need glasses or contact lenses after surgery. This may be true even if you only required a very weak prescription before surgery. If you used reading glasses before surgery, you may still need reading glasses after surgery. Some patients may develop severe dry eye syndrome. As a result of surgery, your eye may not be able to produce enough tears to keep the eye moist and comfortable. Dry eye not only causes discomfort, but can reduce visual quality due to intermittent blurring and other visual symptoms. This condition may be permanent. Intensive drop therapy and use of plugs or other procedures may be required. What are the risks?

9. Other forms of eye surgery include: • Other forms of eye surgery include:. • ALK: This is used to correct vision in people with severe nearsightedness and slight degrees of farsightedness. As in LASIK laser eye surgery, a flap is created in the cornea so that the doctor can reach the underlying tissue. During this procedure, a laser is not used to correct vision. Instead, another incision is made on the sub layer of the cornea to reshape the cornea. • LTK: This is a new laser eye surgery is used to treat farsightedness and astigmatism. During LTK laser eye surgery, a laser beam uses heat to shrink and reshape the cornea. Vision is corrected in a matter of seconds, without any cutting or removal of tissue. • AK: This is not laser eye surgery, but a surgical procedure used to correct astigmatism. The cornea of people who have astigmatism is shaped like a football. AK eye surgery corrects astigmatism by making one or two incisions at the steepest part of the cornea. These incisions cause the cornea to relax and take a more rounded shape. This eye surgery may be used alone, or in combination with other laser eye surgeries such as PRK, LASIK, or RK. • RK: This eye surgery was once one of the most frequently used procedures to correct nearsightedness. However, since the development of more effective laser eye surgeries, such as LASIK and PRK, RK is rarely used today.

10. When physics relates… • Science is a major component in surgeries. Physics is one of the most important components in this surgery. For example light is something we see everyday of our lives. It is everywhere. Its in our houses and it is outside. Light is the range of frequences of electromagnetic waves that stimulate the retina of an eye. Light travels in a straight line in a vaccum. When your body blocks sunlight you see a shawdow. If light from the sun is made visibleby dust particles in the air, the path of the light is seen to be a straight line. The straight line path of light has led to the ray model of light. A ray is a straight line that represents the path of a narrow beam of light.

11. Light • Materials that transmit light waves are called transparent materials. These are objects that can be seen through air, glass, and certain plastics. This material relates to contact lenses. Colors also play a major role. For example many people have brown eyes, grey, green, blue , and hazel eyes. Light can be formed from colored light in many different ways. A pigment is a colored material that absorbs certain colors and transmits or reflects others. A pigment particle is larger than a molecule and can be seen through a microscrope. A pigment is like an eye. They can both be seen through some kind of microscope.

12. Reflections • Reflections are a important factor to eyesight. The law of reflection states that the angle of the reflection is equal to the angle of incidence. Refraction is the bending of light rays at the boundary between two media. Refraction occurs when the incident ray strikes the boundary at an angle. The dutch scientist Willebrord snell stated that a ray of light bends in a such a way that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This is when a ray travels. This is also like looking into a mirror. That’s why eyes are sensitive and should be handled with care. In the retina, sensory cells called rods and cones change the photons of light into electrical signals, which are then transmitted to and interpreted by the brain. The ability to focus the light on the retina depends on the shapes of the cornea and the lens, which are controlled by their inherent shapes, their stretchiness the shape of the eyeball and sets of attached muscles. So, when you look at something, muscles attached to the lens must contract and relax to change the shape of the lens system and keep the object focused on the retina, even when your eyes move. This process is controlled by the nervous system.

13. Solution • Furthermore, lasik eye surgery is a very risky surgery. It can improve your vision, worsen it or even leave it exactly the same. The long term effects are too hazardous to even risk with. Lasik eye surgery is the clear the solution to having good eyesight are the risks worth it? Should people just stay with the original ideas of glasses and avoid possible damage to our eyes?

15. SEE YOU LATER!!!!