When you receive a box of Contact Lenses, you'll find several important pieces of information that will help you understand the specifics of your lenses and how to use them correctly. However, this information can seem complicated if you're not familiar with the technical terms. In this article, we'll explain how to read the information on a box of lenses and what it means to ensure you're wearing the right lenses safely.

At the top of the box, you'll usually find the brand and the type of Contact Lens. These can be Daily Lenses, Monthly Lenses, Toric Lenses (to correct astigmatism), or Multifocal Lenses (for presbyopia). This allows you to know immediately if you have received the correct type of Contact Lens based on your prescription.

Power, often abbreviated as PWR or SPH (for "sphere"), is one of the most important pieces of information to check. It indicates the degree of correction needed for each eye. This number is expressed in diopters (D), which measure the lens's ability to correct your vision. Values can be positive (for hyperopia) or negative (for myopia).

• Example: -2.50 means you are nearsighted, and the lens has a corrective power of 2,50 diopters.

The BC, or Base Curve, is the radius of curvature of the Contact Lens. This measurement is usually expressed in millimeters and determines the curvature of the contact lens to comfortably fit the shape of your eye.

• Example: BC 8.6 means the lens has a radius of curvature of 8,6 mm.

It is essential to follow this measurement, as an improperly fitted Contact Lens could cause irritation, blurred vision, or eye pain.

The diameter of the Contact Lens, abbreviated as DIA, is also expressed in millimeters. It measures the size of the Contact Lens from edge to edge. The diameter affects how well the Contact Lens fits on the eye. A Contact Lens with the wrong diameter may not stay in place properly, resulting in discomfort or poor vision.

• Example: DIA 14.2 means the lens has a diameter of 14,2 mm.

If you have astigmatism, your Contact Lenses must correct not only nearsightedness or farsightedness, but also the irregularity of your corneal curvature. To do this, you'll see two additional parameters on your Contact Lens box:

• CYL (Cylinder): Indicates the power required to correct astigmatism.
• AXIS (Axis): Indicates the orientation of the astigmatism correction, expressed in degrees (from 0 to 180°).

These values are crucial to ensuring clear vision if you have astigmatism.

Contact lenses are made from different materials, and this information is usually mentioned on the box. These can be hydrogel or silicone hydrogel materials, which have different oxygen permeabilities, allowing your eyes to "breathe." Silicone hydrogel contact lenses, for example, are often more comfortable for extended wear. Contact Lens Expiration Date

Like any medical product, contact lenses have an expiration date. You'll often find it next to the EXP label. It is important to never use Contact Lenses after their expiration date, as they may lose their sterility or their ability to properly correct your vision.

• Example: EXP 12/2028 means that the Contact Lenses can be used until December 2028.

The LOT or batch code refers to the production number of your Contact Lenses. This code allows the manufacturing lot to be traced in the event of a problem or product recall. It is primarily used by manufacturers for quality control.

Some Contact Lens boxes specify the replacement frequency, i.e., how long you can wear a pair before discarding it. There are several types of lenses:

• Daily Lenses: Discard after one day of use.
• Weekly Lenses: Replace every two weeks.
• Monthly Lenses: Replace once a month.
• Quarterly Lenses: Replace once every 3 months.
• Semiannual Lenses: Replace once every 6 months.
• Annual Lenses: Replace every year.

Respecting these usage times is crucial to maintaining the health of your eyes and avoiding infections.

On the box, you will also find the number of Contact Lenses it contains. This can be important if you're buying Daily Lenses (where there may be 30 or 90 lenses in a box) or Monthly Lenses (often sold in boxes of 2).

Reading and understanding the information on a box of Contact Lenses is essential to ensure you're wearing the right Contact Lenses and following your eye care professional's recommendations. This information isn't there by accident; it helps ensure comfortable, secure, and effective wear to correct your vision. The next time you receive a box of Contact Lenses, take a few minutes to check every detail. It could make a big difference to your eye health!