subject: Wear Once And Throw Away: 1 Day Acuvue Moist Contact Lenses [print this page] True or False: Leonardo Da Vinci invented contact lenses. This is true; but, he had many ideas that did not exactly work! However, the functional contact lens was first made of blown glass in 1888 by Adolf Frick, a German physician and physiologist. A common modern lens, which is worn once per day and then discarded, appeared twenty-five years ago. And amazingly, that twenty-five-year-old brand is still one of the most popular contact lenses of any type: the 1 Day Acuvue Moist by the Johnson & Johnson company, Vistakon.
The technological advance which made these modern contact lenses possible is an artificial substance called hydrogel. Even though this material is 99.9% water, it has enough substance to support a lens shape through the wide diopter range from -12.00D to +6.00D. Hydrogel is found in many diverse fields and applications including biological engineering, medical and environmental sensors, timed-release delivery of drugs, medical electrodes, explosives, and even in diapers for their ability to absorb urine.
"Daily wear and throw away" contact lenses have recently benefited from the chemical manipulation of its polymer molecules yielding improved lens elasticity, smoothness, durability, and absorbency. A primary drawback keeping a huge segment of consumers from purchasing contact lenses was that otherwise superb lenses blocked too much oxygen from reaching the eye. The successful implementation of silicone into the formula solved this problem by adding oxygen permeability to hydrogel lenses. Additional improvements resulted in the blocking of the sun's ultraviolet type A and ultraviolet type B rays from entering the eye. The blocking ability is eighty-two percent for UV-A and up to ninety-seven percent for UV-B. Further polymer manipulation yielded developments that reduced the allergic response some wearers had to contact lenses. The lenses are so nearly invisible, a light blue tint was necessary just to find them in their holder. They are so light weight that keeping them properly positioned on the eye required a further advance known as a blink-stabilization system. This technology uses the forces naturally occurring in blinking to reposition the lens if its place shifts from optimum.
A comparison of the two highest ranked Acuvue contact lenses makes it clear why choosing between them is not easy. The two lenses are the 1 Day Acuvue Moist and the 1 Day Acuvue TruEye. The former benefits from a higher water content resulting in greater comfort, a wider diopter range, and a twenty-six to thirty percent lower cost. The 1 Day Acuvue TruEye, excels in that it has seventy-two percent greater oxygen permeability, ten percent greater oxygen availability to the cornea (not the same variable as oxygen permeability), and nineteen percent greater blocking of ultraviolet type B solar radiation.
By way of note, it is important to point out that all contact lenses are medical devices and are therefore obtained only with a physician's prescription. Any decision about changing contact lenses should be taken only with a doctor's consultation. One should remove his lenses when there is any discomfort, infection, accident, or illness which affect the eyes and he should report the symptom to a competent eye doctor without delay.
Children are perhaps more averse to contact lenses than adults. Therefore, designing a contact lens they would accept was no easy challenge. Children between the ages of eight and eleven enjoy the sense of independence. Children in this age group are, in fact, able to take care of their "daily wear and dispose" lenses properly by themselves with a minimum of supervision. Again, we have here a development in contact lens design which has continued to catapult this technology into the public mainstream. An affordable lens, which one uses only once before being discarded, has major advantages in preventing discomfort, lens rejection, and storage and handling inconvenience. The demand is so much that literally millions of these types of lenses are manufactured every day.
