What Are Contact Lenses?
Contact lenses can correct refractive errors if a person is having vision problems. They are also frequently used to change the appearance of the eyes. Contact lenses are small thin lenses placed directly over the cornea (eye's surface) to improve a patient's vision.
Types of vision problems that require contact lenses are:
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Nearsightedness (myopia).
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Farsightedness (hyperopia).
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Blurred vision (astigmatism).
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Age-related loss of close-up vision (presbyopia).
Contact lenses are classified in many ways according to their material, primary function, wear schedule, and replacement schedule.
What Are the Types of Contact Lenses?
The two main types of contact lenses:
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Rigid Contact Lenses - Rigid gas permeable lenses are used in certain medical conditions like keratoconus (an eye disorder in which the cornea attains a more conical shape than its normal curvature).
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Soft Contact Lenses - Soft contact lenses are most commonly used nowadays and physiologically more suitable. They are made of silicone hydrogel. These are available in various commercial forms with slight modifications as daily disposable ones, weekly disposable ones, to monthly to yearly disposable ones.
What Are the Tips for Usage of Contact Lenses?
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Contact lenses have to be carefully handled to get better results.
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Wash your hands thoroughly before wearing the lenses.
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Store the lenses in the recommended solution after use.
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Clean, rinse and disinfect your lenses each time after use with lens solution.
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If you notice any redness, burning sensation, or discharge from the eyes, immediately stop wearing the lenses and consult an ophthalmologist.
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Use unexpired lens care solutions for storing lenses and discard the expired ones.
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Keep the lens care solution bottle closed when not in use.
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As a precaution, keep your eyes closed if aerosol products are being used while wearing lenses until the spray has settled.
What Are the Advantages of Contact Lenses?
Contact lenses have some distinct advantages over spectacles:
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Contact lenses are cosmetically more acceptable, especially in high refractive errors where people need to wear thick glasses.
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They give a wider field of vision.
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No prismatic effects are present, as seen with glasses.
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No minimization or magnification of images.
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It can be used even in high anisometropia (high difference in power in both eyes).
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It can correct the vision in irregular astigmatism (example: keratoconus).
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It gives better vision in unilateral or bilateral aphakia (absence of the lens of the eye).
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Contact lenses are preferred in athletes and sports persons who have very active outdoor living.
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The appearance of the color of the eyes can be changed to suit your needs. This can also be used to mask the scars in people having corneal scars.
What Are the Uses of Contact Lenses in Other Ocular Conditions?
Contact lenses are used in several ocular conditions:
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To bandage a small perforation.
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To cover the cornea after suturing.
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To prevent symblepharon (adhesion of eyelids to the eyeball) after chemical injuries.
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In dry eye syndromes.
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To prevent irritation from lashes in case of entropion (a medical condition involving inward folding of the eyelid - mostly the lower eyelid).
What Are the Disadvantages of Contact Lenses?
In spite of having considerable advantages, they are not free of side effects. Most of the side effects are reduced due to newer and well-designed recent developments. A few to mention are:
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Contact lenses need good maintenance. Hygiene during wearing and removal is a must. It has to be stored in contact lens solutions.
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Some people may be allergic to contact lens material. They may develop allergic reactions like conjunctival congestion, itching, watering, immune response keratitis, and conjunctivitis.
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Chances of developing conjunctivitis and a corneal ulcer (acanthamoeba) are higher.
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It may cause corneal opacities by constant microtrauma.
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Contact lenses cause peripheral corneal neovascularization (excessive ingrowth of blood vessels into the cornea).
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It may cause acute and chronic corneal hypoxia (low levels of oxygen).
How to Wear Contact Lenses?
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Wash and dry the hands thoroughly with soap and a clean towel, as discussed earlier.
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Rinse the lens with a solution to remove any dirt or debris.
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If it is a new lens or a daily disposable lens, then no need to rinse with the lens care solution.
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Always apply and remove the lens from the right eye first.
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Place the lens on the tip of the index finger, which is correctly oriented (inside and outside).
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Use the other hand to hold the upper eyelid so it will stop the eye from blinking.
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Pull down the lower eyelid with the help of the other fingers of the applying hand.
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Lift the head up and gently place the lens on the lower part of the eye.
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Slowly release the eyelids and gently close your eyes and roll your eyes in a complete circle to allow the lens to settle and then blink. Check by looking at the mirror to make sure the lens is centered on your eye. If the lens has been appropriately settled, it will be comfortable, and the vision will also be clear.
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But, if the lens feels uncomfortable, remove it and inspect for damage or debris. If it is damaged, discard it. Otherwise, rinse with more solution and reapply.
How to Remove the Contact Lenses?
Do not forget to wash your hands with soap and dry it with a clean towel. Tilt the head towards the ceiling and pull down the lower eyelid.
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Always remove the right side contact lenses first and follow them in the same order while applying and removing them.
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With the help of the index finger, touch the lower edge of the lens and slightly push the lens down to the lower white part of the eye.
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Now gently squeeze the lens between the thumb and the index finger and remove it.
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Remove the other lens also in the same procedure.
How to Avoid Eye Infections Due to Contact Lenses?
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Wash your hands with soap before touching contact lenses or touching your eyes.
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Avoid using fashion lenses like non-prescription color lenses or the over-the-counter contact lens unless an optometrist fits them.
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Do not share your lenses with anyone.
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Wear lenses on the schedule directed by your optometrist.
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Restrict the wearing of contact lenses to a maximum of 8 to 10 hours a day.
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Avoid wearing the lenses during sleep.
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Avoid rubbing the eyes while wearing the contact lenses.
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Do not use tap water to clean the lenses.
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Replace the lens case every three months.
Conclusion:
Even if handled with proper care, contact lenses wearers can end up with dry eyes. If you experience itchiness or redness, remove your contact lenses and use lubricating eye drops. If you experience eye pain or extreme sensitivity to light, see your eye doctor for immediate treatment.
