Cat-eye polish is a magnetic nail polish that contains iron-oxide coated particles, which line up into a bright band of light when a magnet is held over the wet lacquer.
Also known as: cat eye nail polish, cat eye nails, magnetic cat eye, cat eye gel
Cat-eye polish contains magnetic pigment particles, small flakes coated with iron oxide, suspended in the lacquer. While the coat is wet, a magnet is held over the nail. The flakes turn to follow the field lines and gather into a bright band, the eye, with darker colour on either side (The GelBottle Academy).
The band is only fixed once the film sets. In gel, curing under the lamp freezes the particles in place. If you wait too long before curing, the particles drift back and the band blurs (Vettsy). In an air-dry polish the film must set before the particles can settle, so a fast-setting formula and a strong neodymium magnet are needed.
Labels such as 3D and 9D describe the density and intensity of the magnetic pigment. They are marketing terms, not a standard. A 3D cat eye gives a thin, defined single stripe. A 9D gives a bold, thick, highly reflective band, which is the version most seen on social media (Salomé Atelier). A black base makes the band look brightest.
Cat eye appears on every 2025 and 2026 trend list and on the spring 2027 runways in New York, where Sergio Hudson showed a metallic cat-eye zebra and Christian Cowan a purple cat eye with black lines (Bustle). India Anaïs makes a lamp-free magnetic cat-eye lacquer. The first edition is sold out and the next is planned for spring 2027.