How Contact Lenses Are Made
The history of the contact lens reaches back as far as Da Vinci, who sketched samples as early as 1508. The corneal contact lens was suggested later by the famed mathematician and philosopher Rene Descartes, in 1632.
But the modern contact lens really has its beginning around the turn of the 20th century. Adolf Fick gets the credit for inventing the first practical pair in 1887. But, it was Carl Zeiss, the famed lensmaker, who developed a glass contact lens that fit over the cornea that formed the prototype for all later work.
It was still to be several decades before Touhy invented the first plastic corneal lens, using Plexiglas as a material. In 1954 the keratometer was invented, making it possible to take eye measurements without physical contact, eliminating the need for molds from impressions of the eye. While work began in 1952, it wasn't until 1971 that the modern hydrophilic soft contact lenses came on the market.
That word, 'hydrophilic' (which means 'water loving'), is the key to contemporary contact lenses. Today's lenses are made of a plastic polymer (pHEMA) that allows the contact lens to absorb water. That makes it flexible and therefore comfortable.
Some lenses were formed in a molding process called spin-casting, where the plastic is spun into the desired shape. Today, injection molding is more common. Early methods required final shaping with a lathe, but today the process is so accurate the lenses can be made entirely through molding alone.
The lathe process may still be used in some areas of the world, though, especially for hard contact lenses that still make up anywhere up to 25% of those sold. The percentage varies by country. In this method a small circle called a blank is cut from a plastic rod and fastened onto a lathe with wax. It is spun rapidly and cut using a diamond or laser. The lens is then polished with a specially formulated abrasive.
The lens has to be finished to fit the patient's eye exactly. That's carried out by polishing the result into precise curves on both sides of the lens. Today, a computer controls the process, which is kept accurate by being fed information from the individual patient using data gathered during the eye examination.
The lens is then sterilized, often by being boiled in salt water for several hours, which also softens it. They're then packaged in a glass vial containing a sterile saline (salt water) solution. Because the lens material is hydrophilic it absorbs much of the solution, making it up to 75% water in the end. Because the solution is similar to human tears that moisturize the eye, the contact feels good and works well during use.
Research continues into finding materials that are longer lasting, more comfortable and safer to use. Some relatively recent advances, for example, include the Rigid Gas Permeable lens (RGP) invented in 1979, but marketed much later. They allow more oxygen to pass directly to the eye. That makes them more comfortable and safer to use over the long term.
Disposable lenses continue to advance, adding UV absorption to their attributes. Extended wear lenses, too, have improved in the past few years. Many can now be worn continuously for as long as a week to a month. On the leading edge are new implantable contact lenses that are actually placed into the eye and never require changing or cleaning.
Tuesday, September 30, 2008
How Contact Lenses Are Made
Understanding Laser Eye Surgery Risk
There is nothing better or safer then having perfect vision, when it comes to eyesight. There is a lot more to it then just not having to deal with contacts or glasses anymore and blurred vision can really affect your day-to-day living. You are generally stuck unless you carry around spares, if you break your glasses while out or find that you have dropped a contact.
More and more people are turning to laser eye surgery to correct their vision because of all of the inconveniences of not having perfect vision. There must be an understanding that there is a laser eye surgery risk involved, before anyone goes and makes the leap to perfect vision.
There is a lot that must be clearly understood before taking on such a procedure when it comes to laser eye surgery risk. When you are dealing with your eyes, you really should pay extra attention to your chance of encountering a terrible risk, as you could be left blind, of course, as with any type of surgery, there are always risks involved. It is much easier to make an informed decision on whether or not you want to go through with the procedure, once the laser eye surgery risk is clearly understood. It is found that even though there is a laser eye surgery risk involved, many people still go through with the surgery and come out with excellent results.
Risks Involved
When speaking of laser eye surgery, most people believe that lasik eye surgery is the only way to go, but that is just one of the many different eye surgery options out there. As with them all, the lasik eye surgery risk is still there and should be thought about carefully. Most of the eye surgeries have the same type of risks involved, generally speaking. It is important to understand the laser eye surgery risk is there for the few that end up with complications, the chances of true vision-threatening risks are small, but they are still there.
There is the chance of infection, as with any type of surgery, or just the matter of taking a lot longer to heal then expected or desired. there is the small chance that your eyes will be overcorrected or even under corrected, because this type of procedure is not yet a perfect art. Also, a laser eye surgery risk is regression, which means that slowly, over time, the eyes will go back to having the bad vision they started with. Regression is the simplest risk because no real harm is caused and a second surgery is generally acceptable, unlike the other types of risks.
When it comes to laser eye surgery risk, there is a lot that must be clearly known before undergoing such a operation...Read more no cost articles at www.lasereyesurgery.jsgenterprises.com.
Monday, September 29, 2008
Lasik Eye Surgery Tips
The eye is a fragile and delicate structure that supplies the brain with information about the world that we see. Problems affecting the eye range from infections to impaired vision. The image forming mechanism of the eye consists of the cornea, iris and retina. Recent technology has made Lasik Eye Surgery an easy alternative to failing eyes and eye care problems. Impaired vision is the result of a problem with the retina and the cornea, since the brain receives and interprets electrical impulses generated by images falling onto the retina.
Long sightedness is a visual impairment resulting from too short a distance in the eye between the cornea and the retina. Focusing the eye on close objects becomes difficult. Conversely, short sightedness is caused by too long a focal length in the eye or excessive curvature. As a result, the eye will find it hard to see objects at a distance. Astigmatism is another vision disorder that results if the eyeball is not a perfect sphere. We cannot see clearly if the eye is not in the right shape to allow proper focusing of the image attributes on the retina.
All these refractive errors can be corrected using lenses. The power of these lenses is prescribed by our ophthalmologist after testing our eyes. Many people do not like to wear prescription glasses because they are a hassle for those with active lifestyles and they tend to become an eyesore in social situations. For people looking for an alternative to wearing glasses, lasik eye surgery is a fantastic option. Lasik eye surgery, also known as laser in-situ keratomileusis, lifts a section of the cornea allowing a laser to remove any exposed tissue before the cornea section is replaced. If seeking an eye surgery that is less painful and faster to recover from, lasik eye surgery is the way to go.
The only major qualification is a thick cornea, so it is ideal for most. People with vision impairments, such as short sightedness and mild long sightedness, tend to show the best results. For individuals who do not wish to wear corrective lenses, lasik eye surgery is a viable alternative. It is recommended however that individuals who have had lasik eye surgery have regular eye exams to prevent complications from arising. It is also important to remember that the eyes should not be rubbed vigorously following the procedure.
A Holistic Approach To Vision Care
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Improving Your Vision Naturally is a holistic approach to rebuilding your vision.
The analysis of what we see occurs in the brain. Our eyes gather information in the form of light, our brain then takes this information and analysis it, creating our very own world of vision. When we practice vision care it does not only allow us to see better, it also helps us perceive our surrounding better.
Most people will use natural vision improvement to see better. These same people become surprised when they start to improve in unrelated areas, like sports. They will more easily understand what they are reading, perhaps play better if they are musicians. And, they may even become less stressed and become more creative Every person will benefit in a different way from natural vision improvement. But, everyone will benefit. Now, remember, that vision improvement may not work when there are certain conditions, or certain diseases present.
Dr Bates actually was the forefather of natural vision improvement. He developed this theory many years ago.
You can actually do this system from home. There is a reputable Rebuilding Your Vision system available. Depending on your own health condition, the following could be helped by this holistic approach.
Are you nearsighted?
Or, farsighted.
Are you suffering from aging vision?
Or, astigmatism?
Even tired eyes can be helped.
Does bright light bother you?
Computer eye strain (CSS)
Or how aboaut any of these: strabismus and amblyopia, glaucoma, macular degeneration.
Become pro-active with your eye care.
Here are some of the benefits of vision improvement by natural means:
Increase how clear you can see long distance,
See clearer close up,
Learn how to focus quicker,
Your eyes will become healthier, stronger and more fit,
Learn how to manage computer related strain,
Reduce your need for glasses/contacts,
Improve your depth perception,
Adapt much faster to light changes, dark or light,
And, you will have better balance, better results in activities that use your eyes.
We exercise and look after all the other parts of our bodies. Many health minded persons go to the gymn so they can have a healthy body. Why not do the same with our eyes. Let's get involved in our eye care.
Understanding There Are Lasik Eye Surgery Side Effects
Whether you are going for a major surgery that involves an extended stay in a hospital or you are going to the eye doctors for lasik eye surgery, there are always risks involved and it is important to make sure that you have done your homework so that you are fully aware of what you are getting into. Lasik eye surgery side effects are a real thing and it is something that should be taken seriously as the side effects can be anywhere from inconvenient to very painful.
Whether you are taking the time to sit one on one with your eye care professional or you are just doing extensive research on the internet, it is important to make sure that all of your questions and concerns are addressed and answered in a way that you fully understand everything. Most of the procedures done are completed with excellent results and no troubles at all as lasik eye surgery side effects do not happen in most patients. This means your chance for actually being the person that ends up with laser eye surgery complications is small, but it is always present.
The Most Common Problems
The most complained about problem with lasik eye surgery side effects is that of regression. Regression is where your eyes slowly go back to having bad vision, which means that after the surgery, a person could find that they still need to have glasses or contacts. While this is not painful in any way, it can be extremely irritating after everything the person went through in hopes of having better vision. It also means more money and more chances or lasik eye surgery side effects if they want to go through the procedure a second time in hopes of getting it right.
One thing that could be very painful though is that of an infection as infections can cause the healing process to slow down a good bit. It can be messy and painful but normally not vision threatening. While these are the more common of the lasik eye surgery side effects, there are many more to read about.
Some of the side effects are so small that if a person did end up with them, they may not even notice. Either way, it is important to know everything there is to know about lasik eye surgery side effects before heading in to make your appointment. Being informed is the best thing you can do for your eyes and for your overall health.
lasik eye surgery side effects do not happen in most patients as most of the operations done are completed with excellent outcomes and no troubles at all. Also, visit www.lasereyesurgery.jsgenterprises.com.
Sunday, September 28, 2008
Looking Beyond The Eye
This mystery goes straight from the eyes to the brain...and then, where does it go from there?
I am searching and delving into the mystery of the eye. How is it that our eyes are an actual extension of our inner being, a mirror to our soul and spirit? What is it that our eyes are connected to that gives them so much life? So much expression?
The eyes, as we all know by now, are more efficient than any computer created by man. We already know that the eyes are connected to the brain, physically.This connection is the difference between what we see, and what our brain thinks we see. The eyes look...the bran tells us what we see when we look.
This is where the vast field of illusions comes into being. We see what we see, our eyes do not fool us, but our brain does, it turns around and says “nope, that is not what you see...this is what you see”. Amazing isn’t it. Our brain and our eyes are at war. Mostly the brain wins.
But, where does the physical eye connect to so that we are able to see hate in someone's eyes?Let me say it another way. How is it possible that we can express emotions in our eyes? I mean, to actually see this emotion in the physical appearance of the eyes. Where does that come from? How does that happen?
This is why we all like to look into each others eyes when we talk. When we love someone, we can stare for hours into our partner's eyes. Obviously, it’s not just to look at two marble like objects. So, where do our eyes connect so that we can see love in each other, actually see love physically?
What's that about, that our eyes can connect to our soul, our spirit, and convey what we feel?
I remember on one occasion, at someone's funeral, it was the first time I had a true glimpse into a friend's soul, just by looking into their eyes. It is a moment I will never forget. EVER!
What about when you look at someone and you see hate? Is that person allowing you to see this emotion, or, is this emotion a part of the natural process of us being human, and so it naturally shows itself?
We see hate in the eyes, we see love, fear, compassion and even confusion in the eyes.
How often have you looked deep into a friend’s eyes, and seen tenderness?
The eye is a little oval object in our body. Yet, it seems to be able to hold the very essence of our being at any given time.
This mystery goes straight from the eyes to the brain...and then, where does it go from there?
Keep your eyes healthy for as long as you can. Become pro-active in your eye care
What is a Laser Eye Correction Surgery?
People who need restoration of their normal eyesight can choose to get laser eye corrective surgery. If you have been experiencing severe eyesight problems and you want to cure it in a fast and easy way, then you can decide on a corrective laser eye surgery. You can easily regain the lost vision that you have greatly suffered from for years, by subjecting yourself to a minor operation. You can instantly reverse your vision problems and bring it back to a perfect 20/20 vision, through a simple clinical procedure.
Laser Eye Correction Surgery and its Types
Basically, there are two known types of a laser eye correction surgery, namely: the PRK (PhotoRefractive Keratectomy) and LASEK (Laser Assisted Sub-Epithelial Keratomileusis). The two procedures work in an almost similar way. However, there is slight difference with the use of both techniques. Perhaps the first difference would be the method on how to correct the cornea, and the second would be the healing process.
Both follow the same process of numbing the eye by drop instillation, even though they are considered to be two different procedures. While the patient is wide awake, the first step in the surgery is performed. Of course, the patient should be relaxed at the time of the surgery to ensure safety and security while the procedure is being conducted.
A PRK laser eye correction surgery involves a scraping process or ablation of the cornea to remove the "defective" epithelial lining. In the LASEK procedure, a cutting method is used to create a flap or a new layer of cornea instead. The first step of the procedure is the removal of the topmost lining of the cornea. It will be followed later on by growth of a new layer through the Excimer laser. There are varying degrees as to how the reshaping process should come about in every person. If precise measurements (mapping and reshaping) are used better results are to be expected.
Laser Eye Correction Surgery and its Uses
A laser eye correction surgery can be used for several means. Nowadays, it has been widely used by people to correct the simplest or the most complex of problems. If you are financially capable of a laser eye correction surgery, then you can be ready to eliminate your vision problems anytime you want to. All you need to do is find a good doctor who can perform it on you and the rest follows as your surgeons have planned.
Depending on the cause of the condition, Laser eye correction surgery can be used for blindness. More often than not, the patients who subject themselves to the operation are those who are suffering from eyesight problems. If your vision used to be 70/150, it can easily be corrected by laser to a near 20/20. Truly, the laser eye correction surgery is one of the most useful tools ever innovated in man's history.
If you have been experiencing terrible eyesight problems and you want to cure it fast, then you can decide on a laser eye correction surgery. Visit http://www.lasereyesurgery.jsgenterprises.com for more articles.
Saturday, September 27, 2008
Prevent Eye Diseases And Deteriorating Eye Sight With Regular Eye Care Exams.
Being your windows to the world it is important to keep your eyes in good condition. Remember your eyes are subject to wear and tear be it from the ultra violet rays of the sun, pollution and dust in the air, transmittable diseases or stress from looking at a computer screen all day.
We all regularly go to our family doctors for a physical exam to check how our overall health is. The minority take their health for granted. Why is it then that many of us exclude our eye sight from the annual checkup? To guarantee healthy and normal vision, an annual visit to your eye doctor for your eye care exam is important.
Our brain receives sensory information from our eyes giving us a clear picture of our surrounds. Therefore keeping them in optimum shape will ensure proper signals being received by the brain insuring consequential action and reactions. If your vision is deteriorating your life performance will be affected.
We recommend that eye care exams should start from a very early age, that is even babies of 2-6 months should have their eyes checked to correct any abnormalities, while children entering primary school and again when entering secondary school should also have eye care exams which will detect any vision problems allowing corrective action to be taken to rectify the problem.
Unfortunately, as we age it becomes more important to have an eye care exam performed yearly, so that every time you visit your eye doctor they can evaluate any changes in your vision condition and help you correct any difficulties that you may have with your sight. Early diagnosis of problems will decrease the chance of severe damage to our sight.
It is proven that Elderly citizens are more susceptible to vision loss, they should be aware that the probability of having vision disorders increases with age, even though you might not be experiencing any problem, therefore you should visit your eye doctor regularly for an eye care exam.
Eye care exams are painless and informative methods for the assessment of your eyes. The eye doctors will test your visual acuity, (the clarity of your vision). During the eye care exam, the doctor will also check the muscles of the eyes, eye pressure, fluid circulation, retina and general condition of your eyes.. The routine eye examination is not painful or uncomfortable.
Doctors Who Do Eye Care Exams
Ophthalmologists are doctor’s who specialize in the comprehensive care of the eyes and visual system in the prevention of eye disease injury. They are medically trained specialists who can deliver total eye care exams, primary, secondary and tertiary care services and diagnose general diseases of the eyes.
Whereas the Optometrist is the health care professional who provides only primary care services. The services included are the comprehensive eye health and vision examinations: treatment and diagnosis of the vision disorders and eye diseases; the detection of general health problems; they prescribe the glasses, contact lenses, vision therapy, low vision rehabilitation and medications.
How Often Should You Have A Regular Eye Care Exam?
If you are having difficulties with your eyes, pain or visual disturbances or any other problem in the eyes, you should immediately make an appointment to see an eye doctor. However, if you are in good health and no known ailments, no vision problems, you can have an eye exam every two to four years provided your age is below forty. However, for people with diabetes, you need frequent eye examinations to maintain good eye health.
The old adage "prevention is better than a cure”, so make sure you are aware of your vision and if you note any deterioration get on down and have an eye care exam.
Laser Eye Surgery Facts Help Patients Understand The Process
People who grow tired of wearing glasses or believe they look better without them may turn to corrective surgery using laser technology to restore their visual acuity. Before heading out to an all-night laser surgical center people need to get all the laser eye surgery facts they can find to insure they are making the right choice. Not everyone will make a good candidate for lasik surgery and by perusing the available laser eye surgery facts people can quickly determine if they qualify. They can then read about what to expect to determine if they want to follow through with the operation.
Pointing to the success rate of the procedure there are several laser eye surgery facts. Learning what can be expected before the surgery, during the surgery and the appropriate follow up care is an important part of the decision-making process and the laser eye surgery facts can help provide that information as well. If it is being done strictly for cosmetic purposes most insurance policies do not cover the surgery.
Those who wear contacts might have to wait while their eyes return to their normal shape before having the surgery performed, meaning they will have to wear glasses until the day of the operation. They may also have to wear glasses to correct the vision in the one eye that is not corrected according to the available laser eye surgery facts.
Success Rates Are In Potential Patients' Favor
Despite the risks associated with laser surgery, the lasik eye surgery statistics are in favor of the patients as there are many more success stories than there are of surgeries that go horribly wrong. While the risk factors are included in the laser eye surgery facts, the experience and knowledge of the surgeon performing the operation will greatly increase the odds of success.
The patient will be under local anesthetic only with a local sedative for the eye on which the operation is being performed. The patient will go home the same day to begin the healing process in most cases and with the appropriate follow up care, their recovery ends with much better vision then before the operation.
Being able to afford the operational costs may seem daunting for some. The laser eye surgery facts point out that it can be a significant cost savings over the years following the surgery when the cost of eye exams and glasses over their lifetime is calculated.
Thiking about getting laser eye surgery? Check out this awesome no cost article, Laser Eye Surgery Facts. To browse more articles on laser eye surgery visit, http://www.lasereyesurgery.jsgenterprises.com.
Why Myopia is not the End of the World
Myopia occurs in different degrees from minimal to extreme. The more myopic you are the blurrier your vision is at a distance and objects will have to be closer to you so you can see them clearly. Myopia up to 3.0 dioptres (D) is termed mild degree, 3.0 to 6.0D is moderate degree and high degree is 6.0D and over. A dioptre is a measurement of the focusing power of a lens. Myopia progression dropped from .25 diopters per year to .05 diopters per year on the average. Unfortunately, treatment with drops may be worse than the disease.
Myopia is best treated with eyeglasses and contact lenses which compensate for the elongated shape of the eye allowing the light to focus properly on the retina. As children (and their eyes) grow through the teen years, the condition typically worsens and then levels off in adulthood. Myopia or nearsightedness, a condition that results in the inability to see distant objects clearly, affects one in four Americans and is the most common eye disorder in the world with an enormous public health and economic impact. Depending on epidemiologic definition, 3-19% of acquired blindness has been ascribed to myopia. Myopia was the most common cause of blindness in age group 50-59. In age group 60-69, it was second only to diabetic retinopathy, but was considerably more important than that disease in terms of years of blindness.
Myopia tends to run in families, so it is probably inherited. Myopia tends to start in the early teens (earlier for high myopes), and increases as the eye grows in length during puberty. Myopia can be easily diagnosed during a routine eye exam. Usually, a visual acuity test combined with a refraction assessment can not only identify nearsightedness, but can also determine the degree of myopia. Myopia is the medical term for nearsightedness. People with myopia see objects more clearly when they are close to the eye, while distant objects appear blurred or fuzzy, now the good thing is that it can be fix with Lasik Surgery .
Myopia usually occurs between the ages of 8 to 12 years. Since the eyes continue to grow during childhood, nearsightedness almost always occurs before the age of 20. Myopia is mainly caused by the eyeball being longer than normal from side to side. In this condition, distant objects appear blurred but near objects are clear. Myopia is often observed in retinopathy of prematurity (ROP). ROP is seen in 68 percent of infants with low birth weights and over 80 percent of infants born with ROP will be myopic. Then later on they can choose to try contact lenses, but that will not stop the myopia in the long run.
Myopia is a common refractive error, which exists from a young age. A unilateral myopia, with or without amblyopia, might remain undiscovered for a long time. Myopia is a vision defect commonly known as nearsightedness . Those with myopia can see clearly up to a certain distance, then objects begin to appear fuzzy or out of focus. Myopia that first appears in middle age can indicate cataracts. If nearsightedness comes on suddenly and seems to change daily, it could be the result of uncontrolled diabetes.
Myopia is the most common eye problem. It affects as much as 40 percent of the population in the United States and Europe but between 70 and 90 percent of some Asian populations such as Singapore, Japan and Hong Kong. Myopia develops during childhood. The child's eyeball grows too long, which interferes with the light-focusing mechanism. Myopia is a very common condition that affects nearly 30 percent of the U.S. It normally starts to appear between the ages of eight and 12 years old, and almost always before the age of 20.
Acuvue Contact Lenses
Just like other brands and types of contacts, Acuvue lenses were designed to correct many vision problems such as far sight, astigmatism, near sight, and the inability or lack of changing focus from far to near. Acuvue offers you options as well, such as hard lenses, soft lenses, and even toric contact lenses.
To make things better for you, Acuvue contacts have a few different periods of wear. Some of them, such as the Acuvue Advanced, are designed to be worn for a two week period, after which they need to be discarded and replaced with a fresh pair. Some types of Acuvue lenses are made for daily use, which means that you must use a fresh pair each day. Normally, Acuvue contacts are intended for daily use and need to be soaked in solution while you sleep, although there are types that can be left in while you sleep, although you’ll need to clean them on a regular basis.
Although Acuvue contact lenses are considered to be the best contacts you can buy, you should always check with your optician first, as he can tell you which contacts will work best for your eyes. He can also tell you everything you need to know about contacts, and how to take care of them as well. You’ll need to clean your contacts daily, unless you chose to go with the 1day Acuvue contacts, which you’ll change out every day - eliminating the need for cleaning.
Among the many types of Acuvue lenses, those that contain Hydraclear are easily the most popular. Acuvue Advance with Hydraclear are preferred by many, as they are easily among the most comfortable. Hydraclear is a breakthrough in contact lens innovation, helping to prevent your eyes from drying out.
Acuvue contacts are also known for their appearance as well, as they are easily among the best in both comfort and style. Acuvue strives to be the best in contact lenses, which is why their contacts have very little problems. As long as you take care of them, the contacts shouldn’t give you any problems. On the other hand, if you don’t clean them or take care of them as you should, you’ll more than likely encounter some problems.
You can find Acuvue contacts at your local optician’s office, at your local department store (if they sell contacts), or online. Online is the best way to purchase, as you’ll normally get amazing discounts and you’ll find many types of Acuvue contacts that you won’t be able to find locally.
All in all, Acuvue is considered to be the best brand in contact lenses. They have been around for many years, providing those who wear contacts the best in comfort and innovation. If you wear contacts, you are probably already familiar with Acuvue. If you wear contacts but haven’t tried them yet, you really should. Acuvue has many different designs to offer you, and they can easily become your preferred brand if you give them the chance. They are very affordable as well - which makes them an ideal investment for any budget.
