Today, most contact lenses are slightly colored with a visibility tint. A visibility tint is a subtle, translucent coloration added to the contact lens, primarily designed to enhance the visibility of the lens itself. Visibility tints usually do not change the color of your eye significantly; instead, they are used for practical purposes, making it easier to handle, insert, and remove the lenses.
Benefits of Tinted Contact Lenses
- Easier Handling: Visibility tints are particularly beneficial for new contact lens wearers. The faint coloration makes it easier to locate the lens when handling it, reducing the likelihood of dropping or losing the lens.
- Insertion and Removal: When inserting or removing contact lenses, the visibility tint helps you see the lens more clearly. This can be especially helpful for people with dexterity issues or those who have difficulty seeing small objects up close.
- Inside-out Detection: Some visibility tints are applied in combination with a scribe mark that allows wearers to determine if the lens is inside out. Scribe marks (such as 1-2-3 or AV found in many ACUVUE products) serve as a visual cue to correct its orientation before insertion.
How Visibility Tints Work
Visibility tints are applied to contact lenses in a way that doesn't significantly alter the lens's appearance. The tinting process involves incorporating a tinting agent - a tiny amount of FDA-approved, biocompatible colored pigment - into the contact lens material before it is shaped and cured.
Most Common Tints Used
The most common tints used in contact lenses are typically light, translucent colors. These tints are chosen for their subtlety and ability to enhance visibility while maintaining the natural appearance of the eye. Common colors include:
- Light Blue - this is by far the most commonly used tint color
- Light Gray
- Light Green
- Light Violet
- Light Brown
These colors are chosen because they are easy to see against the white background of the eye without affecting the eye's natural appearance.
What Chemicals are used for Colorization?
The chemicals used for colorization in visibility tints are carefully selected to ensure they are safe for the eyes. These tints are typically made from water-soluble, biocompatible dyes that are non-toxic and do not cause irritation. The concentration of dye is minimal, ensuring that it doesn't obscure vision or affect eye health. Manufacturers adhere to strict regulations and standards to guarantee the safety of these dyes for contact lens wearers. Common chemicals used for tinting contact lenses include:
- Iron Oxides: Iron oxide pigments are commonly used in tinting contact lenses. They come in various shades of brown, green, and blue. These pigments are known for their stability and safety when in contact with the eye.
- Phthalocyanine Green: This pigment is often used for green tinted lenses. It is known for its vibrant green color and stability.
- Phthalocyanine Blue: Phthalocyanine blue pigments are used for blue-tinted lenses. They provide a subtle blue tint and are considered safe for ocular use.
- Titanium Dioxide: Titanium dioxide is a white pigment that can be used to create a pale blue or aqua tint when added in small amounts to contact lens materials. It is often used in combination with other pigments to achieve the desired tint color.
- Copper Phthalocyanine: This pigment can be used to create a turquoise or aqua tint in contact lenses.
- Other FDA-Approved Colorants: In addition to the pigments listed above, contact lens manufacturers may use other FDA-approved colorants that are considered safe for contact with the eye. These colorants are chosen based on their stability, biocompatibility, and suitability for the intended tint color.
Do contact lenses with visibility tint change your natural eye color?
No, visibility tints are designed to be extremely subtle. They are not intended to change the color of your eyes. When properly inserted, the tinted part of the lens does not cover the colored part of your eye (iris). Instead, it surrounds the clear center of the lens, which is directly over the pupil. This means that visibility tints are virtually imperceptible to others and do not alter your natural eye color.
It's important to note that visibility tints should not be confused with enhancement tints or color-changing lenses. Enhancement tints are designed to enhance the natural color of your eyes, while color-changing lenses are meant to change the color of your eyes. Visibility tints serve a purely functional purpose and are not intended for cosmetic or vision correction purposes.