Contact lens
Contact lenses are specialized lenses placed directly on the cornea of the eye to correct vision defects. They are commonly referred to as "contacts" and come in various types, primarily soft lenses, which have gained immense popularity for both aesthetic and practical reasons. Contact lenses can be classified into disposable and permanent varieties; disposables are discarded after use, while permanent lenses require regular cleaning to prevent infections. The journey of contact lenses began in the sixteenth century but they became widely available in the late nineteenth century, evolving from glass lenses to modern soft silicone-hydrogel options that allow more oxygen to reach the eye.
Contact lenses are generally not recommended for children under twelve and require a prescription from an eye care professional. Advancements in technology have led to the development of fashionable lenses, including decorative colored variants, though these may not correct vision and can pose risks to eye health. Proper care and adherence to hygiene protocols are crucial to minimize the risk of eye infections, as neglect can lead to serious complications, including vision loss. Overall, contact lenses offer a natural field of vision and convenience, particularly for individuals who lead active lifestyles.
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Contact lens
Contact lenses are small lenses placed directly over the cornea of the eye in order to rectify a vision defect. How to insert them or take them out requires instruction and often a certain amount of practice to gain proficiency in doing so. In the twenty-first century, most contact lenses are the soft variety. Generally referred to in modern culture as "contacts," many varieties are now available. Primarily, there are disposable types as well as permanent varieties. Disposables can be thrown in the garbage after use and, therefore, do not need to be cleaned. Permanent contact lenses require specialized cleaning through a contact lens solution (and keeping the lenses in a special case) to avoid acquiring an eye infection if the lens is dirty. Contact lenses have become increasingly popular for aesthetic reasons. Additionally, people who are active in sports may consider contact lenses a safer option than glasses, given the fragility of glass.
Brief History
The history of contact lenses can be traced back to the sixteenth century. An illustration by Leonardo da Vinci in 1508 shows evidence of a concept of contact lenses. He experimented with a bowl of water and later a funnel-shaped contact lens, demonstrating initiating an optical defect correction. René Descartes, a French scientist, also attempted to devise a contact lens for the eye, but like da Vinci’s model, it was discarded as being impractical. The next known conceptualization appears in 1823 in the design of Sir John Herschel, a British astronomer. The actual manufacturing of a contact lens occurred in 1887. The first product utilized glass and covered the whole area of the eye. The ophthalmologist responsible for inventing the first contact lens to wear on the eyes was Adolf Gaston Eugen Fick from Germany. A plastic contact lens invention took place in the twentieth century. The first rendition was in 1939, followed by a more sophisticated plastic version almost a decade later. This time, the lens was designed to cover the cornea of the eye, rather than the entire eye. By 1971, a revolution came into effect when soft contact lenses were introduced to the international market, including America. A modification of soft lenses appeared in the form of GP or gas permeable contact lenses, becoming popular in the late 1970s. The 1980s saw the US Food and Drug Administration (FDA) approve a soft type of contact lens that a person could wear for extended periods or overnight, as well as the GP overnight version. Further on in that decade, disposable contact lenses and an advanced kind of GP contact lens came into being. Disposable soft lenses were refined in 1996 to benefit contact lens wearers who wished to dispose of their lenses after daily use. Advanced technologies enabled the manufacture of silicone-hydrogel contact lenses and orthokeratology lenses for overnight use in 2002. This was followed by custom-made opportunities for silicone-hydrogel lenses in 2010. Silicone-hydrogel, seen in modern contact lenses, is highly permeable to oxygen and soft and easy to use.
Overview
From the original glass scleral lenses that were manufactured in the late nineteenth century for the rectification of visual irregularities and optical defects, the twentieth and twenty-first centuries saw more comfortable lens types introduced. Soft silicone hydrogel lenses and rigid gas permeable (GP) lenses became commonplace. The issue of oxygen passing through the contact lens to the cornea is particularly pertinent for comfort and safe health care. Advancements in soft silicone hydrogel lenses allow higher amounts of oxygen to reach the cornea than previous types of lenses.
Contact lenses are not recommended for children under the age of twelve. In general, a person wearing contact lenses started by initially wearing glasses and then changing over. Contact lenses require a prescription from a registered eye doctor, following a thorough eye test to ascertain the correct lens for clear vision. An ophthalmologist (medical doctor specializing in eye problems) or an optometrist (licensed eye professional) may conduct the tests. Once a prescription has been received, an optician will make the contact lenses accordingly. The prescription numbers will indicate the eye patient’s vision requirements, as is the case with regular glasses. Contact lenses need to be approved by the US Food and Drug Administration, and it is important that they are purchased from a legally operating contact lens store to avoid placing a potentially hazardous object on the eyes.
According to the Centers for Disease Control and Prevention (CDC), by 2024, 45 million Americans were wearing contact lenses. Of those wearing them in 2016, two-thirds were female. Contact lens wearers under eighteen represented 10 percent of users, with eighteen- to twenty-four-year-olds representing 15 percent, and the twenty-five and forty-five or older age categories representing 50 percent and 25 percent, respectively.
The twenty-first century has seen a proliferation of fashion contact lenses. These include decorative colored lenses that give the wearer’s eyes a different look or color. However, decorative lenses may not correct a vision defect and may be harmful to a person’s eyes.
In addition to the aesthetic and practical benefits of contact lenses, they provide a natural and unobstructed vision field by moving with the eye. However, wearing them may require detailed care with regard to insertion, cleanliness, and additional eye health care appointments. The American Optometric Association provides a detailed tabulation of the advantages and disadvantages of each lens type, from rigid gas-permeable (RGP) to soft flexible plastic daily wear, extended wear (soft or RGP), extended wear soft disposable, and planned replacement soft daily wear contact lenses.
Wearing contact lenses is not without a certain risk. An important factor in eye infections through usage is due to the lenses not being adequately cleaned with the appropriate lens solution or not replacing lenses or cases at optimum times. Serious eye infections associated with contact lenses are not uncommon; the most serious has been known to lead to blindness. It is essential to follow contact lens care instructions in order to avoid such situations.
Bibliography
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