What is a Contact Lens?
Contact lenses are lenses designed as an alternative to glasses to correct refractive errors, placed on the front surface of the cornea. They are used for optical purposes to correct vision by being placed on the corneal surface. In addition to their optical use, contact lenses are also a type of prosthesis used for cosmetic and therapeutic purposes.
What are the Types of Contact Lenses?
Contact lenses are divided into two groups: hard and soft contact lenses. Hard contact lenses are made of a rigid material and have a smaller diameter compared to soft contact lenses. Gas-permeable lenses, also known as semi-rigid or semi-soft lenses, are a type of hard lens. They are similar to soft lenses as they allow oxygen to pass through at varying rates. To adapt to hard lenses, patients must gradually increase the time they wear them each day. Gas-permeable hard lenses are used in eye conditions such as high astigmatism, irregular astigmatism, and keratoconus, with an adaptation period of approximately one month.
Soft contact lenses have a larger diameter compared to hard lenses, covering the colored part of the eye and extending onto the white part when worn. One significant difference between hard and soft lenses is their maintenance. Soft contact lenses must always be stored in a special solution after removal. Since soft lenses contain a high percentage of water, they dry out and become unusable if not kept in a liquid environment. To reduce the risk of infection, soft lenses should be stored in a special solution. There are daily, weekly, monthly, three-month lenses, lenses for one-year daily use, therapeutic lenses used for certain eye conditions, bifocal lenses, and colored lenses. Most lenses used to correct vision are colorless and do not change the appearance of the eye when worn. They correct the refractive error and provide clear vision while being worn.
Bifocal lenses are developed for individuals who need separate glasses for near and distance vision. Another popular group of lenses today is colored lenses. They can be used to correct vision or purely for cosmetic purposes in non-prescription forms. They come in various color options. Prosthetic iris lenses are soft lenses used to camouflage aesthetic defects such as white spots on the cornea caused by previous eye diseases or accidents, or to change eye color for a more natural appearance.
What Should Be Considered When Using Contact Lenses?
- Pay special attention to hand hygiene. Your nails should be clean and neatly trimmed.
- Lenses should be cleaned and rinsed with their solution after each removal, and stored in the recommended storage solution.
- The solution should be replaced every time lenses are removed.
- Do not put lenses in your mouth or moisten them with saliva.
- Put on lenses before applying makeup and remove them carefully before cleaning off makeup.
- Remove your lenses before swimming in the sea or pool; otherwise, lenses may absorb water and create a suitable environment for microbes. Lenses should also be removed before showering.
How to Put on Contact Lenses?
- If you experience any redness, blurred vision, pain, swelling, or severe itching in your eyes, consult your doctor.
- Make sure the contact lens is in your eye before attempting to remove it.
- In its normal position, the lens should sit as it should, with the curve properly aligned.
- If the lens appears flattened when placed on your finger, it may be turned inside out.
- Wash your hands thoroughly, and if possible, ensure your nails are not too long, as shown.
- Make sure the lens you place on your thumb is for the correct eye (right or left).
- Use the middle finger of the same hand to hold your lower lashes and pull down your lower eyelid.
- Use the middle or index finger of your other hand to lift your upper eyelid.
- Place the lens onto your eye.
- Blink a few times to help the lens settle into the center.
- Repeat the same technique for your other eye.
Advantages and Disadvantages of Contact Lenses
Advantages of Contact Lenses:
In addition to the cosmetic benefits and the convenience of not wearing glasses, contact lenses offer better optical advantages compared to glasses.
- For individuals with high refractive errors, contact lenses reduce peripheral visual distortions due to their small size and thickness, as they are worn directly on the eye.
- Patients who have lost the lens in one eye due to surgery or injury (aphakia) often find it difficult to use glasses because they cause significant magnification. Contact lenses, however, have much less magnification, making them easier for the patient to tolerate, allowing them to use both eyes effectively.
- For those without lenses in both eyes, contact lenses provide better peripheral vision and minimal image distortion.
- Patients with keratoconus or other irregular corneas who see little to no improvement with glasses often achieve good vision with contact lenses.
- Contact lenses offer advantages for athletes and individuals with specific job requirements.
- They are recommended for athletes and those engaged in physical activities.
- They are less likely to fall off compared to glasses.
- Contact lenses provide equal or better image quality than glasses.
- They offer a wider field of vision.
- Adaptation is achieved quickly upon first wear.
Disadvantages of Contact Lenses:
- There is an adaptation period. This period is shorter for soft lens users and longer for hard lens users.
- It is important to maintain cleanliness when using contact lenses, as users may experience certain eye health issues.
- They last for a shorter time compared to hard lenses.
- Their structure can change.
- Daily cleaning is required.
- They can cause swelling in the corneal layer.
- Periodic eye examinations are necessary.
- They should be removed when using eye drops or ointments.