Contact lenses offer better vision than glasses in some vision conditions. Some people opt for contact lenses as it gives them a wider field of view. Also, contact lenses don't fog-up in case temperature change and stay unaffected by perspiration or rains. Apart from enhancing the vision,  lenses like coloured or decorative lenses transform the appearance of eyes.

Coloured contact lenses were quite famous when the first time they were introduced. Spectacle frames were losing their grounds then. All those who desired to have light eyes have wholeheartedly shopped for a range of lenses. These coloured contact lenses are famous as cosmetic or decorative contact lenses. They change the appearance of the eyes. From changing the eye's colour or pupil to giving animated or movie character effect, these coloured or cosmetic contact lenses were a hit amongst the masses. The most famous ones were blackout contacts, black sclera contact lenses, cat eyes and zombie eye contacts. These lenses are available in the market with or without vision correction or prescription.

The invention of contact lenses is a boon, and we owe a lot to it. Especially those who are using it for enhancing the vision or for uplifting the appearance must thank this irreplaceable innovation. Today, these lenses are aiding ophthalmological experiments to gauge the progress of eye treatments.

Eye drops or ointments have been assisting the course of treatment of the eyes since a very long time. But it is difficult to gauge the efficacy of the eye drop or ointment administered in the eye. Naturally, eyes are adept to keeps foreign particles out from entering inside. The eyes' natural defence of blinking and tears are effective in clearing the dosage away swiftly.

The scientists have taken a cue from these hindrances, and they have developed a contact lens which changes the colour as the drug is released.

This invention is a visual indicator that will help the eye doctors to check the deliverance of the medication at the intended site of treatment. The scientists have fabricated colour-sensitive contact lenses by using the process of molecular imprinting. This technique helps to match the size and shape of a compound such as medicines. Later, to test the potency, these molecular-imprinted lenses were filled with a drug used for treating glaucoma. When the contacts released the drug, the molecule's architecture changed in the area of drug release as well as the colour change in the iris area of the lenses.

This experiment testifies the fact that these colour changing contacts can control and indicate the controlled release of ophthalmic drugs.