Contact lenses are basically optic devices that are worn directly touching and encompassing the eyeballs, mostly for correcting common visual defects like myopia, hypermetropia, astigmatism and to promote accurate, enhanced eyesight.
Also Read: Astigmatism: Causes, Symptoms And Treatment
In some instances, they are also used merely for cosmetic purposes to flaunt stunning, gorgeous looks, by making the iris – the coloured segment of the eyes around the pupils, appear a different colour. Be it a lighter shade of the natural black, blue or brown, or a rather dramatic effect of tinted green, vibrant purple.
Invention Of Contact Lenses:
The first contact lenses in history were developed in 1949, being made very thin and flimsy, to easily cover the cornea portion of the eyes and could be worn for long periods of up to 16 hours at once. The material used in these contact lenses or Intra Ocular Lenses (IOL) was PolyMethyl MethAcrylate (PMMA). Although PMMA is biocompatible i.e. can be worn directly on human eye tissues, it was found to be rather rigid and the lenses manufactured from them were hence, quite fragile and expensive.
Thus, nowadays, flexible biocompatible materials like silicone and acrylic glass are incorporated in making contact lenses, thereby making them more affordable and easy to use. Currently, contact lenses as an ocular prosthetic apparatus are utilised on a regular basis by over 150 million people across the globe.
Are Contact Lenses Better Than Glasses?
This question is often asked but does not actually have one right answer, at least not on a scientific basis. Whether contact lenses or glasses are the better options is more a matter of choice.
The individual who requires corrective spectacles on a daily basis to see clearly sometimes selects a combination, for example, to wear glasses at work and lenses while heading out to party. And some people just stick to one choice most or all of the time, depending upon their comfort – either glasses or contact lenses.
Many teenagers and young adults feel they look more attractive, pretty or handsome without glasses and hence wear contact lenses as an alternative to augment their aesthetic features. Whereas middle-aged persons, in fact, like to don a pair of glasses to appear cool, calm, wise and mature. Ultimately, it is up to the person to opt for either glasses or contacts, based on their personal preferences.
To compare the two, contact lenses do not accumulate moisture due to external weather conditions of humid heat, rain, snow or even bodily sweating/perspiration processes. This makes them a better option for outdoor adventure activities like trekking, biking, camping or sports. Moreover, an individual using contacts can easily purchase any fancy pair of flashy sunglasses or snazzy goggles, without the need to fit them with customized prescription lenses, in order to look stylish and trendy.
Contact lenses are indeed a boon for the modern generation in many ways and are actually manufactured in various forms to serve distinct purposes. Read on, to know more.
Types Of Contact Lenses:
Contact lenses are usually categorised on the basis of the following:
- Central Function
- Manufacturing Material
- Wear Routine
- Replacement Plan
Central Function:
Refractive Error Lenses
These contact lenses correct for refractive defects like myopia, hypermetropia and ensure light from objects enters the eye at the right intensity or “power” so as to see clearly. Also Read: Myopia: Causes, Symptoms And Treatment
Colour Correction Lenses
Red in colour, “X-Chrom” contact lenses are advantageous for people with colour blindness, to distinguish between varying hues in a better manner.
Cosmetic Contact Lenses
These are purely designer wear and can be used by all people, whether they have an eye defect or not, to modify or lighten the iris colour.
Therapeutic Scleral Lenses
These contact lenses are placed on the sclera, in patients whose cornea is too sensitive, due to conditions like severe dry eye syndrome and microphthalmia.
Therapeutic Soft Lenses
These are specialised optic tools designed to treat non-refractive disorders of the eye such as bullous keratopathy and corneal abrasions.
Manufacturing Material:
Rigid Lens
Called Rigid Gas Permeable Lens or RGP, these are made from unique silicone materials that are oxygen permeable and chemically inert, thus causing no irritation to the eyes.
Soft Lens
These are highly flexible when compared to RGP, being smooth lenses made from silicone hydrogel.
Hybrid Lens
These are a combination wherein a rigid lens or RGP centre portion is surrounded by a soft lens layer.
Wear Routine:
Daily Wear (DW)
These contact lenses can be worn all day and must be removed before going to sleep at night.
Extended Wear (EW)
These kinds of contact lenses can be comfortably worn for up to 6 days at a stretch.
Continuous Wear (CW)
Continuous wear contact lenses are designed such that they can be attached to the eyes for very long durations of 30 days consecutively.
Replacement Plan:
Single-Use
These contact lenses are used only one time in total and are then discarded. They are advantageous in preventing germs, dust and allergens from collecting on the surface of the lens, such as when stored overnight in solution or used for many days.
Long-Term Use
Quarterly or annual lenses are also customized as per the prescription requirements of the individual. This offers the benefit of not having to frequently change, clean and maintain many pairs of contact lenses.
Useful Tips To Maintain Contact Lenses:
Adhering to clean practices helps to avert any infectious pathogens, germs, microbes, dust, and allergens from collecting on the surface of the contact lenses. This is especially vital now, owing to the rampant spread of coronavirus or COVID-19, a contagious viral respiratory ailment.
Follow these guidelines recommended by doctors, optometrists and ophthalmologists, for hygienic handling of contact lenses:
Always wash your hands with a disinfecting handwash or soap and dry them completely, before wearing your contact lenses and after taking them off. This stops the transfer of any dirt particles or germs which cause redness, allergies, itching and infection, from entering the eyes or being retained in the material of the lens.
Contact lenses are made from RGP components, silicone blends and hydrogels, all of which are hydrophobic materials. This implies that they do not mix well in water and hence coming in contact with the clear liquid can actually damage the integrity of the contact lens. So, keep in mind to carefully handle the contact lenses, rinse and store them only inappropriate lens solutions. Also, keep the contact lens case very sterile.
Clean, neat practices to preserve contact lenses certainly avert infections and assist in upholding the delicate material of the optical tool, so as to guarantee sharp, clear vision upon repeated use, every single time.
Additional Precautions To Upkeep Eye Health When Using Lenses
- Do not use any decorative lenses. Avoid buying lenses that are sold only for beauty enhancement at fancy costume stores. These lenses do not serve any purpose, may not suit your eyes, and can damage your eyes permanently
- If you smoke, then you must quit smoking if you are a contact lens wearer. People who smoke are more likely to get vision problems than non-smokers
- Contact lens users should make a chart for themselves to keep track of the usage time of lenses. In case you cannot maintain a time schedule about when to change your lenses, ask your eye doctor to give you a chart for you to keep track of your schedule
- In case you have sudden vision loss, blurred vision, light flashes, or swelling that is getting worse or if you notice an unusual redness in your eyes, discontinue lenses and go to your eye doctor right away
