What Are Contact Lenses? Care Tips and Safety Guide

Blogs Bangkok Eye Hospital

What Are Contact Lenses?

Contact lenses are clear lenses worn directly on the eyes to correct vision problems or enhance appearance. They come in many types, such as soft lenses, rigid gas-permeable (RGP) lenses, daily or monthly lenses, toric lenses for astigmatism, and cosmetic color lenses.

Proper contact lens care includes washing hands thoroughly before handling lenses, cleaning them with contact lens solution after every use, avoiding tap water or saliva, storing them in fresh solution daily, and cleaning the lens case regularly—replacing it every 3 months to prevent eye infections.

When wearing contact lenses, follow your eye doctor’s instructions, avoid sharing lenses, always wash your hands before touching them, and do not wear them for too long or sleep with them in to reduce the risk of irritation and infection.

Contact lenses are a great option for people who want clear vision or a more striking look. However, improper use or poor hygiene can cause serious eye problems. Therefore, it’s important to know how to wear, clean, and care for them correctly to ensure long-term eye health and safety.

What Are Contact Lenses?

Contact lenses are thin, transparent discs placed on the cornea to correct refractive errors—conditions where light entering the eye does not focus properly on the retina, resulting in blurred vision. They can correct nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia (age-related farsightedness).

Types of Contact Lenses

Contact lenses can be categorized based on material and duration of use.

1. Rigid Contact Lenses

Rigid Gas-Permeable (RGP) lenses allow oxygen to pass through to the cornea. They are ideal for people with high astigmatism or keratoconus, helping reshape the cornea for sharper vision.

2. Soft Contact Lenses

Soft lenses are the most popular type due to their comfort and ease of use. They include:

Daily lenses: Single-use lenses discarded after one day; hygienic and low infection risk.
Weekly lenses: Worn daily and replaced every 1–2 weeks.
Monthly lenses: Worn daily and replaced every month.
Extended-wear lenses: Can be worn overnight for several days, but with high infection risk—use only under medical advice.
Toric lenses: Correct astigmatism; available in daily and extended-wear forms.
Color lenses: Available for vision correction or cosmetic purposes; includes fashion lenses, big-eye lenses, UV-blocking, and color vision correction lenses. Always consult an ophthalmologist before use.
Cosmetic lenses: Used purely for appearance—such as cat-eye or vampire effects. Even without vision correction, they should be prescribed by an eye doctor to prevent infections.

3. Other Specialized Lenses

Hybrid lenses: Combine soft and rigid materials to improve comfort and visual clarity; ideal for irregular corneas or aging eyes.
Multifocal lenses: Contain multiple vision zones for both near and far focus; suitable for presbyopia.
Therapeutic lenses: Used after eye surgery to protect and promote corneal healing.

Benefits of Contact Lenses

Provide clear, natural vision without restricting peripheral view, unlike eyeglasses.
Convenient for sports or active lifestyles.
Enhance appearance and confidence, especially with cosmetic color options.

How to Insert Contact Lenses

Wash hands thoroughly with soap and water; dry with a lint-free towel.
Work on a clean surface; close sink drains if working near water.
Start with the same eye every time (e.g., right eye first).
Rinse lens with solution—never use tap water.
Place the lens on your fingertip and check that it’s not inside out (edges should curve upward like a bowl).
Hold upper eyelid with one hand and lower eyelid with the other.
Look straight ahead and gently place the lens on the eye.
Blink slowly to center it. Repeat for the other eye.

How to Remove Contact Lenses

Wash and dry your hands first.
Look up and gently pull down your lower eyelid.
Slide the lens down onto the white part of the eye.
Pinch it gently between your thumb and index finger to remove.
Clean with lens solution before storing.
Replace daily lenses with a new pair as instructed.

Proper Lens Care and Storage

Clean lenses daily with recommended solution.
Rub lenses gently with fingertips to remove residue.
Replace the solution in the case every day.
Clean and air-dry the lens case weekly; replace every 3 months.
Never rinse lenses with tap water, saline, or saliva.
Avoid transferring lens solution into smaller containers.
Discard expired or old solution.

Who Should Avoid Wearing Contact Lenses

Avoid wearing lenses if you have:

Dry eyes or corneal abnormalities
Skin conditions around the eyelids
Thyroid eye disease (protruding eyes)
Poorly controlled diabetes
Allergies to lens materials or cleaning solutions
Tremors, hand coordination problems, or skin issues on fingers/nails

Safe Contact Lens Practices

Get lenses fitted by an eye specialist.
Wash and dry hands before touching lenses.
Do not share or swap lenses.
Avoid swimming or sleeping with lenses on.
Keep solution bottle tips clean.
Wear sunglasses outdoors to reduce light sensitivity.
Use artificial tears to relieve dryness.

Risks of Improper Contact Lens Use

Using lenses incorrectly or unhygienically can cause:

Dry eyes: From prolonged wear or low tear production.
Allergic reactions: From lens materials or cleaning agents.
Conjunctivitis (Eye inflammation): Often from allergies or bacteria.
Corneal abrasions or ulcers: Caused by dryness, poor hygiene, or tight lenses.
Corneal hypoxia: Oxygen deprivation due to extended wear, leading to swelling or infection.
Microbial keratitis: Bacterial infection causing redness, pain, and blurred vision—often from sleeping in lenses.

Summary

Contact lenses offer a convenient and effective way to correct vision and enhance appearance, with various types such as daily, monthly, and color lenses. However, improper use and poor hygiene can lead to eye infections, dryness, and inflammation. Always clean lenses properly, replace solutions regularly, and consult an ophthalmologist if you experience discomfort or redness.

For safe eye care and expert consultation, visit Bangkok Eye Hospital, where our specialists can help ensure your eyes remain healthy and protected.

Frequently Asked Questions (FAQ)

1. Is it safe to wear contact lenses for more than 8 hours?
It’s best not to wear contact lenses longer than 8–9 hours a day. Extended wear can cause dryness, irritation, and inflammation. Use artificial tears to keep eyes moist if wearing them for longer periods.

2. Do contact lenses thin the cornea?
Wearing lenses doesn’t directly affect corneal thickness. However, prolonged use may cause dryness or irritation. Stopping use allows eyes to recover moisture, but corneal thickness remains unchanged.

3. What happens if I sleep with my contact lenses on?
Sleeping in lenses limits oxygen flow to the cornea, especially when eyelids are closed. This increases the risk of redness, irritation, and infection. Always remove lenses before sleeping unless specifically prescribed for overnight wear.

Back

Can You Become Nearsighted Again After LASIK? It is possible to become nearsighted again after LASIK if your vision was not yet stable before the surgery or due to a condition called regression.Common causes include natural changes in vision, individual healing responses, unstable vision prior to surgery, high myopia, or underlying health conditions. When nearsightedness returns after LASIK, possible treatments include enhancement surgery (re-LASIK) if the cornea is thick enough, wearing glasses or contact lenses, or in some cases, considering ICL (Implantable Collamer Lens) implantation as an alternative. Many people who experience vision regression after LASIK may feel disappointed — especially after initially enjoying clear vision. This situation often raises concerns and questions such as: Why did my vision change? Do I need another LASIK? Are there other options?This article explores the possible causes of recurrent myopia after LASIK, the available solutions, and key things to know before deciding on further treatment. Can You Become Nearsighted Again After LASIK? Recurrence of nearsightedness after LASIK is uncommon and usually not serious.Think of it like a healing wound — each person heals differently, even from an identical cut. Similarly, the corneal healing process varies from person to person. In most cases, patients do not experience significant regression. However, for individuals with very high myopia (over -8.00 D) or high astigmatism (over 2.00 D), a mild degree of myopia may return over time — typically around -1.00 D within ten years. This slight regression rarely affects daily life and often still provides better vision than before surgery with glasses. Interestingly, mild nearsightedness that reappears after the age of 40 can even be beneficial, as it helps with near vision (e.g., reading or using a phone) without relying heavily on reading glasses.In general, LASIK results are long-lasting, though natural changes in vision due to aging may still occur over time. Why Can Vision Become Nearsighted Again After LASIK? Regression after LASIK does not necessarily mean the surgery failed. It can occur due to several factors that influence visual stability: 1. Natural Changes in Vision If LASIK is performed before vision stabilizes, refractive changes may continue afterward.This is especially common in younger patients or those with ongoing vision changes.For this reason, doctors typically recommend waiting until vision has been stable for at least 1–2 years before undergoing LASIK. 2. Individual Healing Response Each person’s cornea heals differently. Some may develop epithelial hyperplasia (overgrowth of corneal cells) or subtle biomechanical changes that alter corneal curvature, leading to mild regression. Healing patterns and tissue responses are highly individual. 3. Inaccurate Preoperative Assessment If the initial measurement or laser calibration was slightly off, the correction may not be perfect, leading to residual myopia later.Accurate preoperative evaluation is therefore crucial to ensure precise and lasting outcomes. 4. Severe Myopia Before Surgery Patients with very high myopia require more corneal tissue removal during LASIK, which can increase the likelihood of long-term regression.In such cases, alternative procedures like PRK or ICL implantation may be more suitable to ensure safety and long-term stability. 5. Other Contributing Factors Additional factors that may influence post-LASIK vision include: Pregnancy or breastfeeding, due to hormonal changes that affect vision Chronic diseases such as diabetes with poor sugar control Certain medications, such as corticosteroids or antidepressants, which can impact visual stability How to Care for Your Eyes After LASIK Proper post-operative care is essential to maintain long-term vision results and prevent regression. Below are key recommendations: First Night After LASIK Get adequate rest but avoid touching or rubbing the eyes. Use protective eye shields as instructed by your doctor and do not remove them unless advised. If tears accumulate, gently blot around the shield without touching the eyes. Avoid washing your face with water; use a clean cloth instead. You may shower and brush your teeth, but keep water away from your eyes. First Week After LASIK Use prescribed antibiotic drops and artificial tears as directed. Always wear the protective eye shield when sleeping. Avoid getting dust or water in the eyes and refrain from rubbing them. Avoid makeup around the eyes for at least two weeks. Wear sunglasses outdoors to reduce glare and dryness. After one week, your doctor will usually allow normal face washing and hair washing. Swimming is typically safe after two weeks. What Are the Treatment Options If Myopia Returns After LASIK? If regression occurs, an ophthalmologist will conduct a thorough evaluation to identify the cause and recommend the most suitable approach: Glasses or Contact Lenses The simplest and safest option for mild regression. It avoids surgical risks and allows easy adjustment as vision changes over time. Re-LASIK (Enhancement) If the cornea remains sufficiently thick and healthy, an enhancement LASIK can be performed.The surgeon reopens or recreates the flap and uses a laser to fine-tune the correction.However, additional LASIK carries risks such as increased dryness or corneal thinning, so detailed evaluation is essential. PRK (Photorefractive Keratectomy) Recommended for patients with thin corneas or when flap re-lifting is not feasible.PRK removes the corneal surface directly, but recovery takes longer and may involve temporary discomfort. ICL (Implantable Collamer Lens) An alternative for those with very high myopia or thin corneas.A specialized lens is implanted inside the eye to correct vision without reshaping the cornea.It is a more complex and costly procedure but can be a safe and effective long-term solution. Summary While LASIK is highly effective in correcting nearsightedness, mild regression can occur due to natural eye changes or individual healing differences.Accurate preoperative assessment and advanced surgical technology are key to achieving precise, lasting results. Bangkok Eye Hospital uses cutting-edge equipment and experienced specialists to ensure safe, reliable outcomes and minimize the risk of vision regression — delivering lasting clarity and confidence to every patient. Frequently Asked Questions (FAQ) Is repeat LASIK safe?Yes, enhancement LASIK is generally safe if the cornea is thick enough and the doctor confirms suitability. When should I see a doctor if my vision worsens again?If you notice blurred vision or your eyesight seems to revert to pre-LASIK levels, consult a refractive surgery specialist promptly. Can I prevent vision regression after LASIK?While not always preventable, you can reduce the risk by ensuring your vision is stable for 1–2 years before surgery, choosing an experienced surgeon and reputable facility, and following all postoperative care instructions — including adequate rest and avoiding excessive eye strain.

What Is Thin Cornea? Causes, Symptoms, and Eye Care Tips

A thin cornea refers to a condition where the cornea—the clear, dome-shaped front layer of the eye—has a thickness lower than normal, which can affect vision and overall eye health. This condition may result from various causes such as natural aging, frequent eye rubbing, genetic disorders, or side effects from eye surgeries like LASIK. Common symptoms include blurry vision, frequent changes in prescription, distorted images, and unusually high astigmatism. Understanding the Cornea The cornea is the transparent, curved layer covering the front part of the eye. It helps focus light into the eye for clear vision and serves as a protective barrier against dust and germs. Normally, corneal thickness ranges between 520–550 microns, but it may thin with age. What Is a Thin Cornea? A thin cornea is typically defined as a corneal thickness of less than 500 microns (0.5 mm). It is not necessarily a disease and often requires no treatment. However, thin corneas can affect certain diagnoses—such as glaucoma—since intraocular pressure readings may appear lower than actual values. Corneal thickness also plays an important role in refractive surgery decisions. For example, patients with thin corneas and high refractive errors (nearsightedness or astigmatism) may not be ideal candidates for LASIK, as the remaining corneal tissue after surgery might be too thin. This could increase the risk of complications like keratoconus or corneal ectasia. In such cases, ophthalmologists may recommend alternative procedures such as PRK, ICL, FemtoLASIK, ReLEx SMILE Pro, or NanoLASIK, which preserve more corneal tissue. Therefore, detailed corneal thickness assessment is essential before undergoing LASIK to ensure safe and effective outcomes. Does Wearing Contact Lenses Cause Thinning of the Cornea? Generally, wearing contact lenses correctly does not thin the cornea. However, prolonged use without proper cleaning or rest may lead to oxygen deprivation or corneal infections, which can gradually weaken or thin corneal tissue. Causes of Thin Cornea There are several factors that can lead to corneal thinning: 1. Genetic Conditions Keratoconus: The most common cause, where the cornea gradually thins and bulges outward into a cone shape, leading to irregular astigmatism and blurred vision. It usually appears during the teenage years to early adulthood. Corneal Dystrophies: Such as Pellucid Marginal Degeneration (PMD), where thinning occurs in the lower peripheral cornea. 2. Eye Surgery or Injury Procedures like LASIK or PRK can thin the cornea, especially if excessive corneal tissue is removed. Repeated eye injuries or untreated infections (e.g., corneal ulcers, keratitis) can also cause thinning due to tissue damage. 3. Systemic Diseases and Medication Autoimmune diseases such as Rheumatoid Arthritis or SLE can cause chronic inflammation, leading to corneal thinning.Long-term use of steroid eye drops may also weaken corneal tissue over time. Symptoms of Thin Cornea Corneal thinning often progresses slowly and may not show early signs. Key symptoms include: Blurry or distorted vision Frequent changes in prescription High or irregular astigmatism Difficulty focusing or double vision Diagnosis Thin cornea is often detected during pre-LASIK evaluations.Eye doctors use devices like: Keratometer: Measures corneal curvature and astigmatism. Corneal Topography: Creates a detailed map of corneal thickness and shape. Tomographic Biomechanical Index (TBI): Evaluates corneal strength and risk of ectasia. While early symptoms can hint at the condition, only a comprehensive eye exam by an ophthalmologist can confirm it. Summary Thin cornea is a silent condition that can significantly impact vision if left untreated. Early detection—especially before refractive surgery—is crucial.At Bangkok Eye Hospital, advanced diagnostic tools and experienced specialists ensure accurate corneal thickness evaluation and personalized treatment planning to maintain long-term eye health. FAQ: Frequently Asked Questions About Thin Cornea 1. Can corneal thickness be increased?No, corneal thickness cannot naturally increase as it is determined by the cornea’s internal structure. 2. What happens if thin cornea is left untreated?It may lead to worsening blurred vision, irregular astigmatism, or even corneal ectasia. In severe cases, acute hydrops or corneal perforation may occur, leading to permanent vision loss if untreated. 3. Can thin cornea be prevented?Yes — by avoiding vigorous eye rubbing, maintaining good eye hygiene, limiting contact lens wear time, and having regular eye checkups, especially if there is a family history of corneal diseases.