Contact lens changes colour as medication is released into the eye

US researchers have created a contact lens that changes colour as ophthalmic drugs are released into the eye.

Writing in the American Chemical Society’s Applied Materials & Interfaces journal, the researchers describe how they made colour-sensitive contact lenses using molecular imprinting.

The technique creates cavities within the lens that match the size and shape of a specific compound, such as a medicine.

In experiments, the contact lenses were loaded with the glaucoma medication, timolol.

When the lenses were exposed to artificial tears, the medication was released from the eye. This prompted a colour change by altering the architecture of the molecules.

No dyes were used in the process, limiting the potential for side effects.

The authors highlight that the new lenses could be used to deliver a range of ophthalmic medicines and could potentially be manufactured through 3D printing.

Image credit: American Chemical Society