Eikonal

Bend, bounce, and split beams of light through mirrors, prisms, and lenses. 100 hand-built optical puzzles that solve themselves the instant the physics lines up.

Eikonal is a physics-accurate optical puzzle game. Place and rotate mirrors, prisms, and lenses on a dark canvas, and watch real light rays bend, reflect, and split in real time. There is no submit button — the puzzle recognizes itself as solved the moment your ray field reaches every target.

Named after the eikonal equation, the mathematical foundation of geometric optics, the game simulates light the way it actually behaves: angle of incidence equals angle of reflection, white light disperses into red, green, and blue through a prism, and lenses converge and diverge beams along their true paths.

100 PUZZLES ACROSS 5 CHAPTERS • Reflections — Mirrors. Bounce light to the target. • Refraction — Prisms. Split white light into its spectrum. • Convergence — Lenses. Focus and diverge beams. • Channels — Beam splitters and fiber. Guide multiple paths at once. • Caustics — Diffraction and curves. The master class.

LIGHT THAT FEELS ALIVE Every move updates the entire ray field instantly. Nudge a mirror a degree and the whole scene of light shifts with it. The simulation runs continuously, so solving is a tactile, exploratory act — not a guess-and-check.

DESIGNED FOR iPHONE AND iPAD Smooth, responsive ray tracing. Glowing beams against a near-black field. Built for iOS 17 and later, with full iPad support in every orientation.

NO NOISE No ads. No in-app purchases. No accounts. No internet required. Just you, the light, and the puzzle.

Solve with light.