Macular Degeneration is an eye disease that is often age related. Not much is known about the causes of this disease. How it effects the eye is known. Risk factors have also been determined. Although many treatments are in the early stages there are some treatments that have helped people. Studies and work against the effects of macular degeneration continue.

Macular degeneration is a deterioration of the macula. The macula is at the center of the retina. The retina is the part of the eye that sends visual images to the brain so a person can see. This damage to the macula results in blind spots, blurry or distorted vision. This disease is one of the major visual disease in the United States.

There is not a lot known about macular degeneration. What is known, however is that it is closely linked with aging. There has also been a link found between the disease and a gene variant called complement factor H or CFH. Macular degeneration has two forms: dry or wet. Dry or non-nonvascular macular degeneration is the most common and occurs in 85% to 90% of diagnosis. Wet or nonvascular macular degeneration is a rarer form that results in the worst vision impairments. It is thought that the dry form is caused by thinning of the tissue in the macula. The wet form may be caused by leakage of blood and fluid into the retina.

Since little is known about what exactly causes macular degeneration it is hard to prevent it, but there are some guidelines that have been developed on risk factors that may contribute to the disease. The following list is of those risk factors.

- smoking
- age
- gender (women are at more of a risk)
- family history
- high cholesterol
- race (Caucasians are at more of a risk)
- exposure to ultraviolet light (less is better)

These are just factors that have been studied and shown to play a part in increasing the risk of developing the disease.

There is no cure for macular degeneration. Many medicines and treatments are still in the beginning stages of being studied. If you carry a high risk the best chance of dealing with the disease is getting regular eye exams.

Jeanette Pollock is a freelance author and website owner of eye-care-hq.com. Visit Jeanette’s site to learn more about macular degeneration.

The concept of lenses made from silicone hydrogel was first proposed over 20 years ago. The potential benefits were clear but the technological challenge was as difficult as needing to combine oil and water to produce an optically clear product. Researcher organizations have to date invested considerable academic and financial resources to achieve the high performance soft lenses of today. They have done this quite simply because they see this material as the way forward and the ultimate standard of the future.

At the time of writing, silicone hydrogel lenses are available in the USA from four manufacturers: "Night & Day" and "O2OPTIX" from CIBA Vision, "Pure Vision" from Bausch & Lomb, and "Acuvue OASYS" and "Advance" from J&J Vision Care.

OXYGEN TRANSPORT

So what’s so special about silicone hydrogel as a lens material? Essentially, the great benefit of this material is it’s ability to transport oxygen to the eye and thus maintain proper eye health. Modern contact lens technology is all to do with oxygen permability, which is measured using the "Dk" index. And for optimal oxygen transmission, this must be as high as possible.

The Dk of traditional, non-silicone based hydrogel lenses is directly related to the amount of water that the material can hold, since oxygen dissolves into the water-component of the material and thus diffuses through the lens. The Dk in fact increases logarithmically with increasing water content. Water itself has a Dk of only 80, thus placing a ceiling on the Dk of convential materials, and the original soft contact lens material, polyHEMA, possesses a Dk of only around 10 (with a water content of about 38%).

However, in silicone hydrogels, the relationship between Dk and water content is the opposite. Here higher water content implies lower Dk. With these lenses Dk increases significantly as the silicone content - not water content - of the lens increases. The Dk values of silicone hydrogel contact lenses are much higher than those of older soft lens materials.

SLEEPING IN CONTACT LENSES

According to market data from CIBA Vision, 84% of soft contact lens wearers occasionally sleep with their lenses in, and one-third admit to doing this regularly. 25% of wearers of one to two-week disposable lenses with low oxygen transmissibility occasionally or routinely sleep in their lenses overnight. And 72% of soft contact lens wearers said they would prefer to be allowed to wear their lenses overnight provided it was safe. Thus the demand for lenses with the capablities of silicone hydrogels is evidently very high with almost three-quarters of soft lens wearers wanting to be able to sleep in their lenses.

LENS HANDLING

Silicone hydrogel lenses are significantly more rigid than their conventional counterparts, due to the presence of silicone. This increased rigidity does possess some advantages, making the lenses markedly easier to handle and thus the ideal choice for wearers with a less delicate touch. There is a downside to this however in that the rigidity makes the lenses less prone to adopting the shape of the eye so readily, resulting in the possibility for some of reduced comfort.

REDUCED DEPOSITIONS

Historically, the deposition of proteins and lipids has been a problem with contact lenses. The amount of depositions is essentially linked to the duration of wear, the lens material and the tear composition of each individual wearer. With traditional lenses, a frequent replacement schedule greatly reduces the buildup of harmful deposits.

Silicone hydrogel contact lenses have been proven to offer major benefits in the reduction of protein and lysozyme deposition. Indeed, combined with the correct replacement schedule and appropriate care system, problems associated with protein deposition have become almost a thing of the past.

DRY EYES

A problem frequently encountered by wearers of traditional soft contact lenses is one of a feeling of discomfort and "grittiness" in the eyes towards the end of the day. It has been reported that after one week wearing silicone hydrogel lenses, the quantity of regular soft lens wearers in a particular study group who previously suffered significantly from end-of-day dryness, was reduced dramatically to only 13% of the sample.

LIFESTYLE BENEFITS

Silicone hydrogel contact lenses also provide some benefits that conventional lenses don’t. Continuous wear contact lenses can be particularly beneficial for use by members of certain professions, such as medical workers, police, the armed forces and firefighters who frequently work unpredictable and long hours.

Furthermore, an increasing numbers of contact lens wearers can now enjoy active outdoor lifestyles, enjoying pursuits such as camping and hiking where it is often difficult to handle and didinfect the lenses with the appropriate level of hygiene.

THE FUTURE FOR CONTACT LENSES

There is much evidence to suggest that, owing to their significant benefits over conventional soft lenses, silicone hydrogel lenses will ultimately, and sooner rather than later, displace other types of contact lens as the prefferred choice for both daily and overnight wear for the majority of contact lens wearers. Silicone hydrogel lenses provide a much improved physical performance, excellent handling properties and greater comfort. They might be considered as the ideal lens for general purpose use that exists today and are likely to become the new everyday standard.

BY DR. BIANCA TAVARES

Dr. Tavares is a medical consultant with wide-ranging experience and interests in both traditional and complementary medicine and health care.

She has a particular passion for disseminating quality medical information to the people who count – the patients – and acts in an advisory capacity to numerous journals and health related web sites. Her writing about eye health and contact lenses can be found regularly at Contact Lens Advisor.

This article is copyright by Dr Bianca Tavares. It can be reprinted freely online as long as the entire article with this resource box are included.

Are They Right For You?

People suffering from presbyopia, which makes people unable to read at the usual distance from the eyes and need to place the reading material at a distance further away, were initially prescribed bifocal glasses that could be used to correct two different kinds of problems with the eyes. These bifocal were difficult to manage, so scientists designed contact bifocals for people who wanted to avoid the hassles of bifocal glasses.

The same mechanism is involved in bifocal contact lenses as with bifocal glasses. There are contact lenses available with two different vision options at the top and bottom of the lenses. One advantage with contact lenses is there are lenses where the lens is accommodated with different powers on different parts of the lens. Eyes can adjust the power according to the distance from the object, which is not be possible with glasses where in the maximum number that can be accommodated is two, one type at the top part and the other at the bottom part of the glasses.

Soft and RGP contacts are the two main varieties available for patients suffering from presbyopia. As with the regular wear lenses, they can be disposable or made for long-term usage. The disposable kind is the most popular since the user has the option of using a new pair every day.

Bifocal lenses also come in different designs to accommodate people with different eye problems. With the perfect design, the eyes can adjust the distance and adjust the vision.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

Colored contacts lenses are specialized contacts that are not specifically used for correcting any eye problem. They are primarily used for cosmetic purposes. Many of them do not correct vision and are used to change the color of a person’s eyes, but some colored contact lenses are available for those who need vision correction while enriching their looks.

Contact lenses can be used to enhance the color of the eyes. Existing blue or green colored eyes can be enhanced dramatically by using these lenses. To completely change the eye color, the color-tinted contacts can be used. Though colored contacts do not have a lot of impact on people with intense black or brown eyes, people with light colored eyes would find these to their advantage. Color tinted contacts come in a wide range of colors and are an excellent choice for a short-term change in eye color if the original color gets boring after a while. Some of the more dramatic colors are amethyst and violet. Most of these lenses have a clear center part so that the pupil does not have any problems while the color around the pupil is enhanced subtly.

Popular among the extreme range of cosmetic lenses are the opaque colored lenses. They come in a variety of designs and colors and are mostly used by actors. Lenses that are designed to look like cheetahs or aliens are gaining in popularity.

Latest in the colored contacts range are the light filtering contacts that enhance specific colors like yellow, white, and off-white. These lenses are used during sports like golf when the ball needs to be tracked, or by audience in a tennis match where the ball needs to be kept track off against the background.

It is advised to consult a physician for the correct fitting lenses before buying colored lenses even though they can be bought over the counter in many optical stores. This is to ensure there would be no complications by the usage of the colored lenses later on in the future. Also, colored contacts must be taken care of in the same way as the regular contact lenses.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

Recent market trends show an almost revolutionary boom in the field of contact lenses, not just as a substitute for glasses, but also as cosmetic accessories, such as colored contacts. As the name suggests, the lens comes in direct contact with the pupil do not slip, move, or fall off like glasses.

Contact lenses are seen as more fashionable than most types of glasses. There are a wide variety of contact lenses available including colored contacts, and bifocal contacts.

Contact lenses can be made of different materials and a physician is able to prescribe the most suited one after performing a check up. Although contact lenses suit most people, there are cases where the eye refuses to adjust to the alien body and might result in irritation, itchiness, or other ailments. It is advised to consult a physician before going in for a contact lens fitting. If the contact lenses do not suit the eyes they might result in complications as severe a loss of vision. A physician is able to suggest a correct pair as well as advise on their proper usage.

The three types of contact lenses available are soft, gas permeable, rigid gas permeable (RGP), and hard. Soft and RGP contact lenses are the most preferred even though the hard lenses are also sometimes prescribed. Contact lenses come in different models depending on the usage. Most common are the disposable contact lenses that can be changed either daily or weekly. Also available are monthly disposable ones that can be used for 30 days at a time without needing to be changed. People who cannot afford the disposable ones can go in for the more permanent ones that might last for almost a year or so.

One major thing to consider while shopping for contact lenses is that they are expensive. Glasses do not need the same amount of constant attention that contact lenses require. Contact lenses must be kept clean and washed in solution daily and the user must always be on alert for any irritation or swelling or abrasion due to the lenses. Negligence of such problems might even result in loss of the eye to damage caused to the eye tissue. Also, contact lenses tend to dry the eyes and eye drops must be used frequently to avoid complications in the later stages. This is very important in cases of nightwear or extended wear contact lenses.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

Contact lenses are more expensive than regular glasses. Even when the lenses are available on sale, the solutions to keep them clean and the eye drops would make up for the rest. Despite the high price, many people prefer contacts to glasses.

When it comes to contact lenses, it pays to shop around to find the best deal. Buying contact lenses usually involves paying for a whole package that might include the eye exam, contact lens, the solution, and eye drops. Some eye clinics keep a store of contacts that can be bought from their pharmacies. However, almost all the shops that deal with contact lenses usually have a doctor on board who can do a checkup in the shop itself before recommending the right pair of lenses.

Price checks can be conducted online where many websites provide comparison charts for easier decision making. Another alternative would be to visit a few shops and get a good knowledge of various types, models, and packages available and the wide range of discounts being offered for each. Comparison-shopping helps in getting the best bargain. Any optical shop would be able do a checkup on the premises, so the best option is to compare the prices on the whole deal instead of looking at the price of only one pair of contacts.

Optical shops provide the best deals since they are always trying to make money and increase their market share. It is wise to invest in a well-established contact lens package than in cheaper ones because there might be a possibility of eye problems later on with the cheaper brands. Some online optical shops offer mail-in rebates. They can be ordered online and are sent by a mail order, which can prove to be very convenient. Some websites specialize in taking mail orders and can be very reliable as well.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

People must take good care of their contact lenses. Cleaning the contact lenses and storing them in solution must be a daily ritual to keep them clean and soft and not let them get dry. Also, this would ensure that the lenses are dust free and would not cause any irritation or itchiness in the eyes.

An alternative to this is to use disposable ones. Even though there are contact lenses that can be disposed after a day’s use, they might be very expensive and many people can’t afford them. Contact lens that can be disposed once a week, or a month, or six months or a year are the most popular and affordable types of disposable contact lenses.

Disposable contacts must not be used after the expiration date since this might result in complications in the vision or the eyes. They are also convenient to use and so most physicians tend to prescribe these to the patients. Most popular among the disposable variety are the ones that can be replaced once in every week or two weeks. Also available are the disposable contact lenses that can be disposed once in a month or a quarter, they are known as the frequent replacement lenses. Contact lenses that can be used for at least six months to a year are the reusable lenses. These are the traditional lenses and are not exactly considered to disposable contact lenses.

Disposable lenses are available for daily wear as well as for specialized uses such as for cornea correction during the night. The disposable variety for this particular purpose is also available in the present market.

It is a good practice to dispose of the used lenses at regular intervals or as prescribed by the doctor. This is because the deposits formed in the eye can attach themselves to the contact lenses gradually making them less safe as time passes. Naturally, this would also result in the lenses infecting the eye, causing irritation, itching, and abrasion, as well as affecting the vision adversely.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

Contact lenses are a good substitute for bulky glasses that keep getting misplaced all the time. Even though there has been a dramatic evolution of newer, classier, and more stylish glasses frames, more and more patients are leaning towards using contacts lenses presently.

Contact lenses are expensive compared to regular glasses that are sometimes a onetime investment. Disposable contacts or even permanent contacts need to be changed either once day or a week or in matter of months. Also, they must be cleaned daily with solution and the eyes must be protected against dryness by using eye drops. All these as a package are costlier than glasses.

Many hospitals and charity organizations arrange free eye check up campaigns where they give out free contact lenses instead of glasses. Some of them provide free check ups that are excluded from the lenses price. Also, some opticians give the offer of free lenses with a paid check up, which can help in reducing the prices considerably.

Ophthalmologists and optometrists sometimes form groups at prestigious universities to arrange free eye check up campaigns. These people tend to give out contact lenses to those who need them or at least sell them at considerably lower prices to make them affordable to all those who come in for the check up. In such campaigns, the doctors also assist the patients with the proper usage of the lenses as well as advice on how to take care of the lenses.

Doctors in such camps prefer to give out the long lasting contact lenses instead of the disposable ones to enable the patient to get used to them for some time and then think of investing in the lenses in the future.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.

Contact lenses, like regular glasses, can only be bought by prescription from a qualified ophthalmologist, optometrist, or optician. Now even these physicians can directly supply the contact lens packages at the hospital or through a private practice instead of making the patients go to an optician. Also, most optical shops have an optician in the store for patients who wish to get their eyes checked before buying the proper contact lenses.

Now patients have the option of getting their eyes checked and buying the contact lenses at an optical shop or from the physician himself. Also, ordering the contact lenses via mail is a popular option. Although most people order online without the hassles of visiting an optician, it might not be a good option for first time users.

It is a good decision to shop around for the best deals being provided by the manufacturers of contact lenses. Most leading contact lens manufacturers tend to give some discounts on their products to keep up with the growing competition in the market. Visiting their websites would give insight of all the current offers made by these companies. Also, some companies offer some discount if the customer places an order online by a specified date. Many websites provide comparison charts so that the customers can compare the prices and various deals presently available.

Although most online opticians are reliable when it comes to delivering their products on time, it is important to find the most reliable ones. Faulty contact lenses might result in complication later on and may injure the eye severely in certain cases. It is important to buy the lens online from leading optician chain stores. The product being bought must be 100% reliable, especially when dealing with a sensitive organ like an eye.

In the event the right website cannot be found, the yellow pages are another option for placing a mail order. Many companies provide shipping and delivery of contact lenses of various brands.

The best option is almost always visiting the shops personally. This gives an idea about the price range as well as the variety of contact lenses available in the present market.

Contact Lenses provides detailed information about contact lenses, colored contact lenses, and more. Contact Lenses is affiliated with Age Related Macular Degeneration.