Hiromu Uetake's muscular physique and distinct side-shaved haircut, not to mention the tattoos peeking from below his T-shirt, make him quite a striking sight. But when talking to him, it is his left eye I can't keep my own eyes off. Every now and then there's a flicker of something that makes me stare right into it. When I finally get to see it properly, I realize his iris is blue and there are two bolts of yellow lightning flashing across it.

Uetake, a 34-year-old fashion designer based in Shibuya, Tokyo, is wearing a colored contact lens that he himself designed and that went on the market this summer. Collaborating with Livin Proof, a new contact lens company, Uetake's designs, he hopes, will become a trend in colored contacts.

Using contacts to enhance or change eye color is not new, but it has seen a rise in popularity globally, with prices getting cheaper and both prescription and purely cosmetic ones available from almost any eyewear store.