Vision Correcting Contacts

Blurry vision often develops when the shape of the eye prevents incoming light from focusing precisely on the retina. Vision-correcting contacts sit directly on the tear film over the cornea and bend light before it enters the eye, helping redirect it toward the correct focal point. Different lens powers and designs can correct nearsightedness, farsightedness, astigmatism, and presbyopia.

Since contact lenses move with the eyes, they can provide a wider field of clear vision than glasses and cause less peripheral distortion for some wearers. Clear results still depend on using the exact prescribed power, material, curvature, and lens design, so contacts require a separate fitting rather than simply copying an eyeglass prescription.

Contact lens replacement schedules tell you how long a pair may be reused before it should be discarded. The schedule starts when you open the lenses, not according to the number of times you wear them, so a two-week pair generally shouldn't be stretched across several months of occasional use.

Daily, bi-weekly, and monthly contacts can all correct common vision problems, but they involve different care routines and ongoing costs. Always follow the schedule prescribed for your specific lenses rather than wearing them until they begin to feel uncomfortable.

Daily Disposable Contacts

Wear a fresh pair each day and throw it away after removal. Daily lenses require no cleaning or storage, making them a convenient choice for frequent travelers, occasional wearers, and anyone who prefers a simpler routine.

Bi-Weekly Contacts

Replace the lenses every two weeks after opening, following the exact schedule provided by your eye care professional. They must be removed, cleaned, disinfected, and stored properly after each day of wear unless specifically approved for a different wearing schedule.

Monthly Contacts

Use the same pair for up to one month after opening, then discard it even if it was only worn occasionally. Monthly lenses require consistent nightly care and a clean storage case, but their longer replacement cycle may suit people who wear contacts regularly.

Soft and rigid gas-permeable contacts can both correct refractive errors, but they differ in fit, feel, durability, and the type of vision they may provide. The better choice depends on your prescription, corneal shape, comfort preferences, and how consistently you're willing to follow the required care routine.

Soft Contact Lenses

Soft lenses are made from flexible, water-containing materials that conform closely to the eye. They usually feel comfortable quickly and are available in a wide range of prescriptions, replacement schedules, and specialized designs, making them a common choice for everyday wear.

Rigid Gas-Permeable Lenses

Rigid gas-permeable lenses hold their shape on the eye while still allowing oxygen to reach the cornea. They can provide especially sharp, stable vision and may work well for stronger prescriptions, irregular corneas, or vision that isn't fully corrected with standard soft lenses.

Comfort and Adjustment

Soft lenses generally require less adaptation, while rigid lenses may feel more noticeable at first and can take several days or weeks to become comfortable. Consistent wear is often important during the adjustment period, since taking long breaks may make rigid lenses feel unfamiliar again.

A contact lens prescription includes more than vision power. It also identifies the specific lens measurements and design approved for your eyes after a fitting, which is why an eyeglass prescription can't be used as a substitute.

The exact abbreviations may vary by prescription, and specialized lenses can include extra values for astigmatism or presbyopia. Use the information below as a guide, but order only the lens and parameters written by your eye care professional.

OD and OS

OD refers to the right eye, while OS refers to the left. Each eye may have a different prescription.

Power or Sphere

This value is measured in diopters. A minus sign generally corrects nearsightedness, while a plus sign generally corrects farsightedness.

Base Curve

The base curve describes the curvature of the contact lens. It helps the lens sit properly on the eye and is usually shown in millimeters.

Diameter

Diameter indicates the overall width of the lens in millimeters. Along with the base curve, it affects how the lens fits and centers on the eye.

Cylinder and Axis

These values appear on prescriptions for astigmatism. Cylinder shows the amount of astigmatism correction, while axis identifies the direction of that correction.

ADD

ADD appears on multifocal contact lens prescriptions for presbyopia. It indicates the additional magnifying power needed for near vision and may be shown as a numerical value or as categories such as Low, Medium, or High.

Lens Name or Material

A contact lens prescription usually identifies the exact lens material, manufacturer, or approved product. Contact lenses with similar powers aren't automatically interchangeable since their fit and design can differ.

Issue and Expiration Dates

Check that the prescription is still valid before ordering. Prescribers must provide patients with a copy after the contact lens fitting is complete, and sellers must verify that the prescription hasn't expired.

Dry, sensitive, or tired eyes can make contact lens wear less comfortable, especially after long hours of screen use, time in air-conditioned rooms, or exposure to dry air. The right lens depends on more than water content alone, so an eye care professional may also consider the material, surface wettability, replacement schedule, fit, tear film, and recommended wearing time.

Silicone Hydrogel Material

Silicone hydrogel lenses allow more oxygen to pass through the lens to the cornea than traditional hydrogel materials, which can support healthier everyday wear. However, higher oxygen transmission doesn't automatically make a lens comfortable for every person with dry or sensitive eyes. Comfort also depends on how well the lens stays moist, how it interacts with your tears, and whether its shape and replacement schedule suit your eyes.

Vision-correcting contacts may need to be refitted when they no longer provide consistently clear, comfortable vision. Signs can include recurring blur, lenses that shift or decenter, increasing dryness, frequent irritation, or discomfort that develops sooner than it used to. Changes in your prescription, corneal shape, tear film, eye health, medications, or wearing habits can also affect how well a lens fits, even when the same type worked comfortably before. Contact lenses are individually fitted, so switching to a different material, design, or replacement schedule requires professional evaluation rather than choosing a substitute based on power alone.

Schedule an eye exam if your vision has gradually become less sharp or your lenses repeatedly feel uncomfortable. Remove them immediately and contact an eye care professional if you develop sudden blurry vision, marked redness, worsening pain, light sensitivity, excessive tearing, or unusual discharge, since these symptoms may indicate more than a routine fitting issue. Regular checkups also help identify changes that may not cause obvious symptoms yet and confirm that the lenses still move, center, and interact safely with the surface of your eyes.

Although both prescriptions correct your vision, they aren't interchangeable. Contact lenses sit directly on the eye, while glasses rest several millimeters in front of it, so the required power and prescription details may differ.

Glasses Prescriptions Focus on Optical Power

An eyeglass prescription commonly lists sphere, cylinder, axis, and sometimes prism or ADD values. It doesn't include the measurements needed to fit a lens safely on the surface of the eye.

Contact Lens Prescriptions Include Fit and Lens Details

A contact lens prescription includes the prescribed power along with information such as the lens type, base curve, diameter, and designated product or material. Contacts are individually fitted, so you shouldn't order them using only the numbers from a glasses prescription.

Putting in and removing prescription contacts safely becomes easier with practice and a consistent routine. Always wash and dry your hands before handling your lenses, and never use water or saliva to clean or store them.

1. Wash and dry your hands. Use soap and water, then dry your hands thoroughly with a clean, lint-free towel before touching your lenses.

2. Inspect the lens before inserting it. Check that it's clean, undamaged, and not inside out before placing it on your eye.

3. Insert the lens gently. Hold your eyelids open, place the lens on the eye, and blink a few times until it centers comfortably.

4. Remove the lens carefully. Slide it onto the white part of your eye and gently pinch it between your thumb and index finger. Avoid using your fingernails.

5. Clean or discard the lens properly. Throw away daily disposable lenses after removal. Clean, disinfect, and store reusable lenses with fresh solution according to the prescribed care instructions.

6. Stop wearing the lenses if your eyes become irritated. Remove them immediately if you notice pain, persistent redness, light sensitivity, unusual discharge, or sudden blurred vision, and contact an eye care professional if the symptoms don't improve.

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Types of Contact Lenses. U.S. Food and Drug Administration. https://www.fda.gov/medical-devices/contact-lenses/types-contact-lenses. Published January 16, 2018. Accessed July 22, 2026.