Traits

any combination of colours (even rainbow) pupils can be a solid colour or multiple colours as well

any object possible single or both eyes

either floral or crystal structures (for mineryes) single or both eyes

glass sight filled with liquid (objects can swim inside) single or both eyes

any constellations or random star bits

any amount of eyes, can be placed on the body as well

can be elemental (fire, ice, electric etc.)

any colour possible

no visible depiction of an eye trait

light coloured sclera, darker coloured iris

dark coloured sclera, lighter coloured iris

very dark coloured sclera, lighter coloured iris

any shape, any amount of pupils

any shape, different shape in each eye is possible

different coloured eyes (not actually a trait but to show the possibility)

any amount of ridges

intertwined set of teeth oni or eastern dragon like look

bat shaped nose, two big fangs

any kind of object

animated holographic features that can display anything