Your Corneas Are As Unique As You Are

Buying shoes online is always a gamble. A stylish pair of shoes may have plenty of positive reviews and come in your size, yet are incredibly uncomfortable when they finally arrive on your doorstep. Other factors beyond size, like width and arch type, affect the fit of shoes. In fact, most people have to try on several pairs of shoes before finding the perfect pair.

The same type of process applies to fitting contact lenses. Contact lenses rest on the corneas, the clear rounded tissue that covers your iris and pupil.

Every cornea is unique. Some curve more than others or are irregularly shaped. Contact lenses that are too flat or too curved for your eyes are bound to be uncomfortable and may not provide the crisp, clear vision you expect from your contacts. Poorly fitting lenses rub against your cornea or move every time you blink, causing irritation that may make you wonder if contact lenses are really worth the trouble.

During a contact lens fitting, your optometrist measures the size of your pupil and iris and the curvature of the cornea. Your eye doctor uses that information to select contact lenses that best fit your eyes. At the end of the fitting, you’ll be given a trial pair of contact lenses to try for a few weeks. Although the first trial pair of contact lenses is the ideal option for many people, others may need to try another brand or type of contact lenses.

Your Comfort Depends on Your Fitting

In addition to determining the curvature of your cornea, your eye doctor also evaluates your tear film. If your eyes tend to be dry, contact lenses designed to retain moisture and keep tears from evaporating too soon may be the best option.

During the fitting, your optometrist also considers other factors such as:

• Protein Buildup. Proteins in tears cling to contact lenses, causing irritation and worsening dryness. If protein deposits tend to build up on your lenses quickly, your optometrist may recommend daily disposable lenses rather than extended-wear lenses. Daily disposable lenses are worn once and thrown out, while extended-wear lenses are cleaned every night and worn for a week to a month before being replaced.
• Refractive Errors. Your eye doctor will suggest contact lenses that provide the clearest vision for refractive errors, like myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. For example, if you have astigmatism, you may need toric contact lenses that fit the irregular shape of your cornea.

Wondering why your near vision has become blurry? If you’re over 40, you may have presbyopia. The age-related vision condition only affects near vision and is the reason people need reading glasses. If presbyopia is an issue for you, you may benefit from multi-focal contact lenses that combine multiple prescriptions in one contact lens. Multi-focal contact lenses provide sharp near, far, and intermediate vision.

Nothing Stays the Same Forever

During your annual comprehensive vision examination and contact lens fitting, your eye doctor looks for changes in your eyes that could affect the fit, comfort, and acuity (visual sharpness) of your lenses. For example, astigmatism tends to worsen with age.

Fifty-five percent of people with astigmatism experienced changes starting in their mid-40s, while 41% didn’t have any changes until their mid-50s, according to research published in Review of Optometry in 2023. A new prescription and new contact lenses could improve your vision and accommodate the change in the shape of your cornea.

Dry eye can also become a problem as you get older. The American Optometric Association notes that dry eyes are a normal part of aging and affect most people over 65. Switching to contact lenses with a higher moisture content could help you avoid irritation due to dry eye.

Is it time for your next eye exam and contact lens fitting? Contact our office to schedule an appointment with the eye doctor.

Sources:

• Review of Optometry: Ocular Astigmatism Changes Occur After Mid-40s, 9/27/2023 https://www.reviewofoptometry.com/news/article/ocular-astigmatism-changes-occur-after-mid40s
• American Optometric Association: Dry Eye https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/dry-eye?sso=y
• All About Vision: Eyeglass Exam vs. Contact Lens Exam: What’s the Difference?, 8/14/2020 https://www.allaboutvision.com/eye-exams/eyeglasses-vs-contacts-exam
• American Academy of Ophthalmology: How Do I Prevent My Contact Lens from Moving Up Under My Top Eyelid?, 12/3/2018 https://www.aao.org/eye-health/ask-ophthalmologist-q/how-do-i-prevent-my-contact-lens-from-moving-up-un
• Optometry Magazine: What Unique Challenges Arise When Fitting Contact Lenses?, 7/18/2024 https://optometrymagazine.com/qa/what-unique-challenges-arise-when-fitting-contact-lenses