Contact lenses in the simplest manner can be described as an aid to the eyes. The contact lenses or contacts as they are generally called help us to make blurred vision clear and make you able to see clearly. In the present scenario, contact lenses are one of the popular aids to enhance our vision. Due to the size and special features they have become famous among youth and most of the youth prefer contact lenses instead of eyeglasses. They are small in size and are fixed directly on the retina of the eyes. They help to enhance the beauty of eyes as it is a common understanding among youth that they don’t look smarter wearing eyeglasses so that is the reason why they prefer contact lenses instead of eyeglasses.
About Contact Lenses
Contact lenses are thin apparent discs made up of plastic material that are finely assembled on the cornea of the eye to enhance vision. Some of the refractive inaccuracies that are corrected by contact lenses are myopia and hypermetropia. Myopia and hypermetropia are also known as nearsightedness and farsightedness respectively. They help to make clear the blurred vision of the eyes in cases when our eyes are not able to focus light correctly on the retina. They are finely mould and polished pieces of glasses that are meant to fix directly onto our eyes to clarify vision.
According to different perspectives contact lenses are categorized into different types. For example, contact lenses can be classified on the basis of their prime role that how they should work to enhance our vision, substance of the lenses that what they are made up of, wearing plan that how long they should be worn prior to removing it and the substitution plan that how long before a lens needs replacement.
According to the functioning or the prime role, contact lenses are identified as corrective contact lenses. These lenses are especially designed to enhance vision by correcting the refractive errors of our eyes. Different lenses are used for the correction of different kind of refractive errors. Refractive errors are also known as refraction errors. They are the errors of our eye lenses in which they are not able to focus the light on the retina. Different kind of refraction errors are myopia, hyperopia, cylindrical errors, astigmatism, presbyopia, etc. For different kind of errors, different contact lenses are used so that they are able to focus light clearly on the retina. That is due to the reason that differently structured lenses bend the light differently according to their structures such as some of them bend the light rays horizontally and some of them vertically and so on. For example, spherically shaped contact lenses bend the light consistently in all directions. Generally, they are used to correct myopia and hyperopia. Toric contact lenses are able to focus the light rays horizontally in comparison to vertically due to specific kind of structure. That is why they are used for the correction of astigmatism refraction error. Apart from this, some special kind of spherical stiff lenses are also used for the correction of astigmatism refraction error. During the designing of toric lenses designers always keep one thing in mind that lens should not rotate the ideal coalition of light rays focusing on the retina. For the correction of presbyopia refraction error, two approaches are used, multifocal and mono vision. According to these approaches, two types of contact lenses are used for the correction of presbyopia refraction error. Multifocal contact lenses are somewhat similar to bifocals or progressive lenses as they have multiple focal points. Generally, multifocal contact lenses are designed for constant viewing through the center of the lens but some multifocal lenses are designed with a certain shift in focal point of the lenses. Mono vision lens are special kind of lenses that have one focal point per lens.
Apart from above stated refractive errors, eyes do have some other errors, for example, colour paucity also known as colour blindness. In this type of error, person is not able to distinguish between different colours. To remove this type of error from the eyes, a special kind of contact lenses is named ‘X-chrome’. Though these contact lenses are not able to remove colour blindness effect but still they allow the user to differentiate between the colours. Chroma Gen lenses correct colour blindness but they have certain limitations such as they are not so effective during night. Cosmetic contact lenses are second type of lenses according to the functioning of contact lenses. They also correct refraction errors but generally are used to make the eyes more beautiful and attractive. They generally have light shades of colour and due to the colour of the lenses eyes get attractive colour too and hence they make your eyes more beautiful and attractive. Cosmetic contact lenses are also known as ornamental contact lenses. There are certain complications related to the comfortable and easy use of cosmetic lenses. These complications are similar to those that occur during the use of other contact lenses, for example annoyance, infection and visual redness. That is why it is advised that prior to the use of contact lenses you should always have a check-up of your eyes with an eye specialist so that your eyes should be examined thoroughly and the doctor will advise you to wear suitable contact lenses for your eyes. Sclera lenses are being used as cosmetic lenses in film and entertainment industry to change the facade of the eyes of the film stars.
According to the functioning of the contact lenses, the third kind of contact lenses is therapeutic or remedial contact lenses. They are used for managing and handling non-refractive errors of the eye such as wounded or contaminated cornea owing several reasons. They are also used as a cure for several eye diseases, for example, corneal abrasions and erosion, dry eyes, corneal edema, anterior corneal dystrophy, neurotrophic keratoconjunctivitis and many more. Apart from above, few contact lenses have been designed just to implant drugs to our eyes. They are placed in contact with the cornea and slowly they pass on the drug or the medicine to the cornea and consequently it is transferred to our eyes.
There are basically three types of lenses according to the property of the material used for constructing the lenses. They are rigid, soft and hybrid lenses. Lenses are generally made from polymethyl methacrylate also known as PMMA or Perspex/Plexiglas. These lenses are also known as rigid or hard lenses as the material they are made up of is hard in nature. The drawback with this type of lenses is that they can’t permit the oxygen to pass through the cornea that can cause certain unfavorable clinical happenings and can lead to problems. Earlier, oxygen-permeable lenses were manufactured and were known as rigid gas permeable or ‘RGP’ lenses. So, a spherical rigid contact lens can be used for the correction of astigmatism. For the formation of front-toric, back-toric or bitoric, rigid lenses can be used. Rigid lenses are somewhat different from spherical lenses as one or both planes of the lenses can work as a solution to toric errors. Rigid lenses can also be used as a solution to keratoconus that is a kind of corneal irregularity. They help the patients with keratoconus to see through better in comparison to normal glasses. There is an advantage with the rigid lenses over soft lenses that they are more chemically inert in nature so they can be worn in tougher environments.
Soft lenses need less time for adaption in comparison to hard lenses. Earlier, hydrogel lenses were used as soft lenses but now the polymers of soft lenses have achieved oxygen permeability and lens wet ability that has significantly improved the overall comfort. There is a drawback with the hydrogel lenses that they are slightly harder and the surface can be hydrophobic. These features can affect the comfort and can cause certain problems.
Apart from soft and rigid, there are hybrid lenses too. Normally, hybrid lenses have a rigid center and a soft skirt. A special technique is used for the formation of hybrid lenses named piggybacking. In this technique, a rigid lens smaller in size is backed on the surface of soft lens that is larger in size. Rigid lens helps in correction of the vision and soft lens provides comfort.
According to the wearing schedule, lenses can be categorized as daily wear, extended wear and continuous wear. Daily wear are those that can be worn for a day and should be removed before going to sleep. Extended wear contact lenses could be worn continuously throughout the day and while sleeping too. Generally, they are designed to be worn for six consecutive nights. Now-a-days, we can have contact lenses that can be worn up to 30 nights continuously. This kind of lens is known as continuous wear contact lens. They are made up of special kind of materials for example silicone hydrogels. Extended and continuous wear contact lenses are generally high in oxygen permeability. Due to this property, they can be worn for the whole night, even while sleeping. When we are awake, the eyes are open and hence they permit oxygen from the air to enter into eyes and mix into the tears and pass from the lenses to the cornea and when we are sleeping, a little oxygen is provided with the help of blood vessels at the back of eyelid. Generally, while sleeping contact lens prevents the uninterrupted supply of oxygen to the cornea that cause disorder named corneal hypoxia and consequently can have certain complications and may affect the clarity of vision. To counter these problems, extended and continuous wear contact lenses have some properties that can allow passage of oxygen to the cornea 5-6 times more in comparison to normal soft contact lenses that make the eyes healthy and allow comfort even during sleeping. That is why it is advised to wear contact lenses during day time only.
According to the replacement schedule, lenses are categorized as single use or daily throwaway that are generally discarded after using them just for one day. This is due to the reason that they are not able to retain their quality after using for one day and so repeated uses are avoided for these kinds of lenses. Single use lenses are designed thinner and lighter to provide comfort to the eyes. Single use lenses are generally used by those persons who use contact lenses very rarely. Other contact lenses according to replacement schedule are those that need to be replaced after a use of two-three weeks. Annual lenses such as rigid gas permeable lenses need to be replaced at least after a year use as they have long life and can last for few years. There are a few lenses that are more durable so they need to be replaced after wearing then for 5-10 years. PMMA is an example of these types of lenses. They can be worn for 5 to 10 years without any replacement. Same type of material can be used to manufacture the lenses having different replacement schedules. Though the material is same but there is some difference in the manufacturing procedure that distinguishes lenses according to their replacement schedules. Generally, it is the manufacturing procedure that decides whether the lens is ‘daily disposable’ or it is going to be the one that is suggested for two-three weeks use only.
Generally, soft contact lenses are available in the market in numbers but the rigid contact lenses are manufactured on the order of the customers. This is due to the reason that soft contact lenses are used by a large number of people but the rigid lenses need accurate specifications for manufacturing that differs from patient to patient. Some of the contact lenses that differ according to their manufacturing process are spin-cast lenses, diamond turning and molded.
Spin-cast lenses are soft contact lenses that are manufactured by a process in which liquid silicone is revolved in a revolving pattern at a lofty pace.
Diamond turning contact lenses are manufactured by cutting and polishing the lenses on a CNC lathe machine. First, a cylindrical disk is held in the chops of the lathe machine that has an industrial-category diamond as the cutting equipment. The RPM of the CNC lathe machine is around 6000 and it cuts and eliminates the intended amount of mater from the lens. Then the concave surface or the inner surface of the lens is polished with some rough paste such as oil and with the help of small polyester cotton made ball that is turning at high speed. The convex or the reverse surface of the lens is polished and cut with the help of same process. The above said procedure is used to shape the rigid lenses and in some cases for the soft lenses but the difference in cutting during the manufacturing of soft lens is the dehydrated polymer that is used to cut soft lenses.
Molding method is used for the production of some brands of soft contact lenses. Revolving molds are used and the melted matter is added and is shaped with the help of centrifugal forces. Manufacturing process of the lenses differs from company to company.
Best Sellers of Contact Lenses at Lenskart
Though there are many companies in the market that produces contact lenses but still the users prefer to use only those contact lenses that are manufactured by some major brands in this area. The major manufacturers of contact lenses are from USA and other foreign countries. If you want to buy contact lenses then you must have to look for some of the top brands of the world as they provide a class and quality to their products. The major brands of the world are considered to be the best sellers of contact lenses. If your want to have an overview of these brands prior to buying then you can go to lenskart.com. There you can search for Contact Lenses India and this will lead you to those brands and products that are available in India. You can easily get the details of the desired contact lenses with price and range that will help you to select a correct piece for your eyes according to your budget and specifications. Some of the best sellers you will find at lenskart.com are Johnson & Johnson, Ciba Vision, Bausch & Lomb, Cooper Vision, Aryan, Acme Yearly Toric, Celebrations, Silk Lens, Fresh Kon, Biomedics and Glamour Eye.
Why are These Best Sellers Best of all other Brands?
The major brands of contact lenses at lenkart.com are known as best seller brands as they are well known for their quality and reasonable price. That is the reason why they are more trusted brands from the point of view of the customers. Though there are so many local brands in the market that offer contact lenses but you are advised to use products only from the trusted brands as they maintain their quality according to their price value. The materials used by these brands are up to the mark and the manufacturing process is also reliable and authenticated.
Why is Lenskart the Right Place to Buy Contact Lenses?
The answer to this question is not just few words but in reality is a matter of experience that you have while purchasing contact lenses from lenskart.com. You can get your Contact Lenses Online with the help of just few clicks on lenskart.com. It will definitely help you to get your desired piece at reasonable prices. The patron services of lenskart.com are more user friendly and help their customers and advice them after the delivery of the product. It will be a more suitable option to buy contact lenses from lenskart.com in comparison to roaming here and there in the market in search of a product you desire to buy.