How Do Contact Lenses Work?

Understanding Contact Lenses

Contact lenses are thin, curved lenses placed directly on the surface of the eye to correct vision. They work by refracting (bending) light in such a way that it focuses properly on the retina, the light-sensitive layer at the back of the eye. This corrects various refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia.

Types of Contact Lenses

There are several types of contact lenses designed to suit different vision needs and lifestyle preferences. Here’s an overview of the main categories:

1. Soft Contact Lenses

Soft contact lenses are made of flexible, water-absorbing materials called hydrogels. They are comfortable to wear and allow oxygen to pass through to the cornea, which is essential for eye health.

• Daily Disposable: These lenses are worn once and discarded at the end of the day. They are convenient and hygienic, reducing the risk of infections.
• Bi-weekly/Monthly: These lenses are designed to be worn for a specific period (two weeks or one month) before being replaced. They require regular cleaning and storage.
• Extended Wear: Some soft lenses can be worn continuously, even while sleeping, for up to a week or more. However, not all users are suitable for extended wear, and these lenses require careful monitoring by an eye care professional.

2. Rigid Gas Permeable (RGP) Lenses

RGP lenses are made of durable plastic that allows oxygen to pass through. They provide clear, crisp vision, especially for people with astigmatism or keratoconus. Although they may take longer to get used to compared to soft lenses, they are more durable and can last longer.

3. Toric Lenses

Toric lenses are specially designed to correct astigmatism. They have different powers in different meridians of the lens, which helps to correct the uneven curvature of the cornea or lens in astigmatic eyes.

4. Multifocal/Bifocal Lenses

These lenses are designed for people with presbyopia, a condition that typically occurs with age, making it difficult to focus on close objects. Multifocal lenses have multiple zones of different powers, allowing for clear vision at various distances.

How Contact Lenses Correct Vision

Contact lenses correct vision by altering the direction of light rays entering the eye. Here’s how they work for different refractive errors:

• Myopia (Nearsightedness): In myopia, the eyeball is too long, causing light to focus in front of the retina. Contact lenses correct this by diverging light rays so that they focus directly on the retina.
• Hyperopia (Farsightedness): In hyperopia, the eyeball is too short, causing light to focus behind the retina. Contact lenses correct this by converging light rays to bring the focus forward onto the retina.
• Astigmatism: Astigmatism is caused by an irregularly shaped cornea or lens, leading to distorted vision. Toric contact lenses correct this by having different powers in different meridians of the lens, aligning the light properly on the retina.
• Presbyopia: Presbyopia is an age-related condition where the eye’s lens loses its ability to focus on close objects. Multifocal or bifocal contact lenses provide different lens powers to accommodate both near and distance vision.

Fitting and Prescription

Getting the right fit and prescription is crucial for the effectiveness and comfort of contact lenses. Here’s what to expect during a contact lens fitting:

1. Comprehensive Eye Exam

Before fitting contact lenses, a comprehensive eye exam is conducted to assess your vision and overall eye health. This includes measuring visual acuity, checking for refractive errors, and examining the health of the cornea and other eye structures.

2. Corneal Measurements

Precise measurements of the curvature of your cornea are taken using a keratometer or corneal topographer. These measurements help in selecting the appropriate lens size and shape for a comfortable fit.

3. Trial Lenses

You will be given trial lenses to wear for a short period. This allows the eye doctor to assess the fit and comfort of the lenses and make any necessary adjustments. You may need to try several types or brands before finding the best match.

4. Instruction and Training

If you are new to contact lenses, you will receive training on how to insert, remove, and care for your lenses. Proper hygiene and handling are essential to prevent infections and ensure the longevity of the lenses.

5. Follow-Up

A follow-up appointment is usually scheduled to check the fit and performance of the lenses after a few days or weeks of wear. Any issues or discomfort can be addressed, and adjustments can be made if needed.

Caring for Your Contact Lenses

Proper care and maintenance of contact lenses are vital to prevent infections and maintain eye health. Here are some key tips:

• Wash Your Hands: Always wash your hands thoroughly with soap and water before handling your lenses. This helps to avoid transferring dirt and bacteria to your eyes.
• Clean and Disinfect: Use the recommended contact lens solution to clean and disinfect your lenses daily. Avoid using water or saliva to clean your lenses.
• Follow the Schedule: Adhere to the prescribed wearing and replacement schedule for your lenses. Do not wear lenses longer than recommended.
• Store Properly: Store your lenses in a clean contact lens case filled with fresh solution. Replace the case every three months to prevent bacterial contamination.
• Avoid Sleeping in Lenses: Unless your lenses are specifically designed for extended wear, avoid sleeping in them to reduce the risk of infection.
• Stay Hydrated: Keep your eyes hydrated by blinking frequently and using rewetting drops if needed, especially in dry environments or when using digital devices.

Common Issues and Troubleshooting

Despite proper care, you may encounter some common issues with contact lenses. Here’s how to address them:

• Dry Eyes: If your eyes feel dry, use lubricating eye drops recommended by your eye doctor. Make sure you stay hydrated and take breaks from screen time.
• Irritation or Redness: If you experience irritation or redness, remove your lenses and inspect them for damage or debris. Clean them thoroughly before reinserting. If the issue persists, consult your eye doctor.
• Blurry Vision: Blurry vision can result from dirty lenses, incorrect prescription, or improper fit. Ensure your lenses are clean and correctly positioned on your eye. If the problem continues, schedule an appointment with your eye doctor.
• Infections: Signs of an eye infection include redness, pain, discharge, and sensitivity to light. Remove your lenses immediately and seek medical attention if you suspect an infection.

Your Contact Lenses and Tennessee Eye Care 

Contact lenses are a convenient and effective way to correct vision, offering numerous benefits for those who prefer them over eyeglasses. Understanding how contact lenses work, the different types available, and proper care techniques are essential for maintaining eye health and achieving optimal vision correction.

At Tennessee Eye Care, we are dedicated to providing personalized care and expert guidance for all your contact lens needs. Whether you are a first-time user or an experienced wearer, our team is here to ensure you have the best possible experience with your contact lenses. Schedule an appointment with us today to explore your options and find the perfect lenses for your lifestyle.

For more information or to book an appointment, contact us today. Your eyes deserve the best care, and we are here to provide it.