What is hanbunakaruikusundame? Or in short, sundame eyes?
Hanbunakaruikusundame (Half-Bright, Half-Dull Eyes) is an emerging design concept in anime and character illustration characterized by asymmetrical eyes that differ in color, shape, and visual rendering.
While frequently confused with standard heterochromia—which is strictly restricted to variations in iris pigmentation—sundame eyes incorporate structural differences, such as contrasting line weights, pupil geometries, and lighting highlights between the left and right eyes.
Derived from a compound of Japanese descriptors:
Literally translated as "half bright, half dull eyes." The nomenclature highlights a stylistic juxtaposition of visual weights rather than strict, literal color assignments; it does not mean one eye is universally bright and the other is dark, but rather emphasizes a striking structural and thematic contrast.
When applying this concept to a character design, one eye typically features vibrant rendering—such as high-saturation highlights, complex gradients, and wide or dynamic geometry—while the opposing eye utilizes a subdued treatment, such as flat shading, muted tones, geometric simplification, or hollowed-out pupils to create immediate psychological friction.
Beyond pure aesthetics, sundame eyes can be utilized as a visual narrative device to represent internal duality, fractured identity, emotional detachment in one half of a character's persona, or an uncanny, supernatural transformation that has only partially taken root.
Creators can explore multiple tiers of asymmetry within this framework, ranging from subtle geometric discrepancies (such as a slight change in eyelid shape or pupil dilation) to extreme contrasts where one eye looks glossy and alive while the other appears mechanical, glitching, or weeping.