Contact Lenses
An Optometrist or ophthalmologist can determine if wearing contact lenses would work effectively, and can measure the eyes for a perfect fit. In the United States contact lenses can only be legally purchased, by a valid written prescription from an ophthalmologist. Avoid purchases from the Internet, since many websites are unreliable or do not verify prescriptions. There are different kinds of contact lenses. The doctor provides information how to take care of the contact lenses, and how to insert them into the eyes. Contact lenses are either flipped inside or out. Wearing contact lenses inside out, there is a slight discomfort, and lenses do not fit. Placing a contact lens, on one finger, and observing if there is a perfect half circle, without edge sticking out, then contact lens is fine to insert. Also, if the contact lenses form a “U” with the top edges appear out, then correctly able to insert. Contact lenses are held in place by tears, on the surface of the eye.
Different types of Contact Lenses:
Hard Contact Lenses are the least type of desirable lenses. These lenses are made of hard plastic material, are either non-gas permeable or gas permeable. Hard Contacts will last five to ten years. Unfortunately hard to insert, take out, and adjust. Non – gas Permeable lenses do not allow oxygen to reach the cornea, which limits the time the lenses can be worn. The longer time oxygen does not pass through the eye, to the cornea may result in eye damage. Gas permeable lenses allow oxygen to flow through the eye to the cornea, which allows for longer use, and more comfort. These lenses tend to cost less over their life span (except up front cost are higher), and a sharper vision than soft contacts. Rigid gas — permeable lenses are similar to hard contact lenses, except made of better material, allow more oxygen to pass through then soft contact lenses, made of hard plastic which provides a sharp vision, and corrects most vision problems. Require some time to get adjusted, and not recommended for high physical activities.
Soft Lenses are made of flexible polymer — plastic materials, and contain 25 to 79 percent water. Oxygen flows easily to the cornea, and easily adjustable. Offered in a variety of colors, and need to be replaced once a day. These lenses will not last very long, won’t correct some vision problems, and not durable. Extended Soft Lenses, allow user to wear them for seven to thirty days. More oxygen passes through the eye to the cornea. Example of these type of lenses: ‘Focus NIGHT & DAY’ lenses, which capable of using 30 nights of continuous usage. The lenses are made from silicone hydrogel, which allows six times more oxygen to pass through the eye, and less likely to dry up then ordinary soft lenses. Also, these type of lenses are bio – compatible, which decrease protein, and bacteria accumulation, but does not eliminate some from having eye problems wearing this type of soft lenses.
Disposable lenses are used for a limited time, and then discarded. Usually these lenses can be replaced every two weeks, but there are some lenses that can be replaced, after three months. Disposable lenses are more comfortable, and can be worn over night, but need to be cleaned, and disinfected, to prevent eye problems. These lenses are made by companies, which include Johnson & Johnson, and Hydron.
Bifocal contact lenses are available in both soft and rigid gas permeable materials. The lenses are used by those that have presbyopia, which happens when aging eye is unable to focus on near objects. This condition tends to begin around age of 40.
Toric lenses are available for those that have astigmatism (The cornea curvature is asymmetrical, where the eye is shaped like a football or egg, instead of a baseball), can’t wear soft lenses. These lenses are available for anyone that has either myobia (nearsightedness) or hyperopia (farsightedness), and are kept more stable in the eye, when blinking or looking around. Toric contact lenses, will take longer time to determine the proper fitting, and will cost more then other types of lenses. Toric lenses are available for disposable use, and available in different colors to enhance eye color.
Monovision Contact lenses an alternative to bifocal contacts. The Optometrist fits in one eye contact for near vision, and in the other eye a contact for distance vision. Advantages are a simple fitting and less expensive
Some Contact lenses are manufactured to prevent ultraviolet light. However these contact lenses only cover the cornea, and not the entire eye. Sunglasses can protect the entire eye. Orthokeratolgy reshapes the cornea with contact lenses, worn while sleeping. This treatment helps those that are nearsighted, and have astigmatism. The Food and Drug Administration approved overnight corneal reshaping manufactured lenses by two companies: Bausch & Lomb’s new Vision Shaping Treatment (VST), and Cornel Refrective Therapy (CRT) made by Paragon Vision Sciences. Eye professionals that have been certified by either company are authorized to measure anyone, for this type of lenses. Expected by the end of 2005, there will be 2,000 people, fitted corneal reshaping contact lenses. The reshaping of the cornea takes between two to three weeks. Afterwards, the contact lenses need to be worn at night or during part of the day, to maintain the corrective results. Otherwise, the cornea will regress to the original shape or closeness. These lenses are not suitable for anyone that wants to eliminate wearing contact lenses. Those that wear these lenses, which will undergo laser eye surgery, are required to stop using the corneal reshaping lenses, possibly for several months, until the cornea regress, back to the normal shape.
Many people, and especially teenagers with perfect vision will wear, colored contact lenses to enhance their appearance. These lenses are available in a variety of colors, which include violet, jade, green or royal blue. During Halloween these colored contact lenses, become more popular. Ciba Vision Company sells Newvues Contact lenses, which are available in different colors.
When cleaning contact lenses, always wash hands first. Use recommended quality eye lenses care products, and clean the lenses as often as possible. Place the contact lenses overnight in a storage case, filled with fresh disinfecting solution. Also, clean the lens case with a saline solution. When wearing contact lenses, sometimes place drops of lubricate, which keeps the eye moist, and provide more comfort wearing the lenses.
