Most people probably know that colored contact lenses are fashion accessories, used to change or improve the apparent eye color of people who wear them. Fashion is one good reason for using them, but there are also many scientific reasons that they are often used to change the appearance of the eye. The extension of their science into areas beyond fashion is fascinating, and it makes colored contact lenses a topic that arouses interest in many areas of study because of their potential for technology and human health. Here, we investigate the science of these lenses and the reasons why they can be used for purposes other than fashion.

How Colored Contact Lenses Work

Colored contact lenses are worn to change the surface color of the eye. The technology behind these contact lenses is similar to regular contact lenses, only the lens material is transparent but also contains a layer of color. This color layer can be a combination of different shades and is configured with structural patterns similar to how an iris is structured, so that it appears natural.

There are three main types of colored contact lenses:

1. Opaque Lenses

These lenses are suitable for a full color changing. These could be a fantastic option for dark eyes people who are curious about trying lighter shades such as blue or green. Full color changing with opaque lenses use solid colors or patterns to totally hide the original eye color.

2. Enhancement Lenses

These lenses are semi-translucent and are meant to intensify the wearer’s natural eye color or produce only very minor changes. These lenses are most effective on individuals with light colored eyes to add dimension or slight hue alterations to produce the effect of making eyes appear lighter or more vibrant.

3. Visibility Tint Lenses

These are only very slightly tinted, usually green or blue, and while they aren’t really colored in the way that colored contact lenses are, they make wearing lenses easier to manage and see as the lenses enter and exit the eye.

The Technology Behind the Tint

The color of colored lenses is created by means of a selection of biocompatible dyes, approved by the FDA (the US Food and Drug Administration), which are deposited between the two layers of the lens material. Since the dye is not in contact with the eye, it does not cause irritation and does not lead to allergic reactions. The color pattern of the lens is often structured to copy the natural radial pattern of the iris, with the color distribution varying in intensity for a more natural effect.

Furthermore, with improvements in printing technology, it now becomes possible for manufacturers to make lenses with more complex patterns and multiple colors to make the lenses look more natural. A few lenses have a darker limbal ring around the edge and this gives a more natural structure to the lenses as well as a slight ‘expansion effect’.

Medical and Therapeutic Uses of Colored Contact Lenses

Aside from aesthetics enhancements, colored contact lenses have also been employed for a number of medical and therapeutic purposes:

Color Vision Deficiency (CVD)

Some varieties of colored lenses, such as chromagen lenses, are designed to help correct certain forms of color blindness (a form of color vision deficiency) by altering the light that enters the eye to improve the contrast between different colors so that the observer can easily discriminate between colors that would otherwise appear similar.

Photophobia and Light Sensitivity

For the millions of people who suffer from photophobia (light sensitivity) – a common symptom of migraines and ocular albinism – tinted lenses will reduce the amount of light entering the eye and, as a result, diminish some of the distress and compromise that can come from operating in bright environments.

Aniridia and Irregular Pupils

Tinted lenses may be useful in treating aniridia or irregular pupils that don’t allow the eye to fully cover the pupil from bright light. In these cases, the lenses often not only make the eye look more normal, they can also improve visual function because the lens reduces light scatter and improves contrast perception.

Prosthetic Use

Prosthetic colored lenses can be fitted over damaged or scarred eyes to give the appearance of a more normal eye. A truly natural effect can be achieved if the colored lens is made specifically for the individual and matched to the appearance of that person’s other eye. This is particularly appropriate when the prosthesis is intended for someone who has lost an eye.

Safety Considerations for Colored Contact Lenses

Although colored contacts can indeed enhance appearance and serve therapeutic purposes, their use must be monitored in a way that preserves the health of the eye. Here are a number of practical safety considerations:

Prescription Requirement

Colored contacts are actually medical devices that should be prescribed by an optometrist or eye-care professional. If the lenses are being worn for a purely cosmetic reason and do not correct an eyesight problem, an eye test is still required to make sure the lenses fit the eye well and are not causing problems. Make sure that you know how to read your contact lens prescription.

Proper Hygiene and Care

The lenses have to be kept as clean as possible. Wash your hands before wearing or handling lenses, use the appropriate cleaning solutions, and keep the lenses in a clean case. Worn, used lenses can cause eye infections, corneal abrasions or other serious eye conditions.

Avoid Sharing Lenses

Sharing contact lenses of any kind – even colored contacts – is never safe. Each time you wear your lenses, they can accumulate bacteria and other pathogens that are transferred to your eyes. Sharing lenses with someone else allows your friends to share these pathogens.

Limit Wear Time

Opaque colored lenses can significantly reduce the amount of oxygen reaching the cornea compared with clear lenses, so it’s important to follow the wear schedule and give your eyes a break.

Colored Lenses as a Fashion Statement

The fashion and entertainment industries have embraced colored lenses too, using them to create the dramatic, cat-eyed look of an actor or to bring out the green or brown eyes of a model. Many social media influencers and celebrities use colored lenses to match their eye color to the rest of their makeup, or to wear fun, outlandish colors.

The craze had spawned a whole range of colored contacts – both natural-looking and bold, bright shades to some that let the wearers’ eyeballs appear to have cat eyes or zombie eyes, and are popular especially around Halloween or cosplay events.

More Than an Optical Decoration

While changing eye-color can be a fashionable experience, colored contact lenses offer more than an optical decoration. They are a new frontier where fashion, technology and medical science merge in creating a product that can adapt to different requirements, fulfilling aesthetic wishes, correcting vision deficiencies, and contributing to medical treatments.

But always exercise good judgment, and consult your eye care provider if you’re planning to use colored contact lenses for the first time. With the right lenses and care, you can try on a world of looks and benefits – and an entirely new world, as well.