The phenomenon of speshul eyes is common in fanfiction, particularly in badfic. It is also known formally as idiochromia: the trait of having eyes with an 'individual' or 'unique' color. It is not medically related to the real-life trait of heterochromia iridum, the trait of having eyes each with a different color, even if multiple colors are expressed in eyes displaying idiochromia.
All eyes mentioned in this article are assumed to be human eyes, but in badfic, speshul eyes may occur in any species... even species with eyes that do not vary.
Although all eyes are unique, and even in real life eyes with interesting or unexpected traits may occur, speshul eyes strain believability with their appearance. Eyes that are two different colors are rare, but exist, and eyes that seem to change color depending on the light or depending on clothing/makeup worn can be considered normal. However, many people possess eyes with these traits; they are not special or unique in concept. Normally little attention is called to them beyond establishing a character's appearance, and they blend happily into the setting.
Speshul eyes never blend into the setting, but rather are used to justify why a character should stand out or be notable. This is often a very cheap sentiment: a character that would otherwise have to be noted by her deeds and personality sometimes is validated as notable simply by the color of her eyes... a trait that she was (presumably) born with and did not choose.
Speshul eyes are a common Sue trait, but not an indicator of Suedom on their own. They are a symptom, but not the disease... even if the most dramatic variations of speshul eyes are really hard to justify.
Variations of Speshul Eyes
Overly Meaningful Eyes
Although the use of color symbolism with eyes is a practice nearly as old as people describing eyes in the first place, speshul eyes can take it too far. It goes beyond 'blue for purity' or 'brown for earthiness' or 'red for danger' and instead treads into using such symbolism as a way to define the character, rather than having the character be clarified by the symbolism. Many historical Sues or canon Sues display this aspect of idiochromia, exhibiting 'limpid, innocent blue eyes' or 'dangerously dark' eyes every other paragraph of the story.
Overly Figurative Eyes
Often an artifact of purple prose, eyes are a common subject of figurative language. While metaphor and simile can be used to describe eyes to great effect if used sparingly, speshul eyes once again take it too far. The term 'stormy eyes' is modest; expect to see things like 'seafoam-spray' eyes, or 'eyes like the blackest pits of the darkest abyss in all of oblivion' or some such tomfoolery. Sometimes the metaphor is in the form of a verb; 'His eyes blazed,' for instance. While this is acceptable, if overdone it can become bad. And if it is bad, expect a word world to interpret it literally.
For the same reason that some smut writers seem to detest using anatomical terms, other writers seem to detest the word 'eyes.' Perhaps because they feel they have to use the word so many times (she stared with her emerald EYES, and slowly she turned her EYES to the side becomingly, as if calling you over with her EYES) and they want to avoid repetition, or because they feel that the word 'eyes' is unpoetic, they unleash an army of synonyms, some of them less than apt. Known substitutes for 'eyes' include 'orbs,' 'lamps,' 'sightspheres,' 'headlights,' 'lights,' 'oculars,' and 'peepers.'
Eye colors that could not occur in the canon involved can be deemed speshul, impossible eyes. In some canons, a bright red or silver eye color might be acceptable, but in others, it would not be... or would require a very good reason to make sense. Sometimes this is invoked accidentally, when two or more eye colors are mentioned as being one color, or when a color is misspelled. See Sue Color Spectrum for such aberrations of color.
Eyes that (beyond the rare trait of heterochromia) are multiple colors at the same time, sometimes described as a 'burst' or a 'rainbow' or a 'kaleidoscope,' are some of the most obnoxious of speshul eyes in existence. Slightly tamer multicolor eyes might be two colors only rarely found in nature (pink and turquoise, for instance).
Eyes that change color beyond what can be considered normal are usually speshul. Unless there is an in-universe explanation that makes sense, eyes that make dramatic color shifts is one of the most well-known Mary Sue traits. Sometimes the change in eye color indicates a change in 'state' (perhaps a hidden power has manifested) or even in simple mood.
Eyes That Do Things
If a character's eyes literally sparkle, glow, flash, or fire energy blasts, then there isn't any sense in pressing the matter. These are speshul eyes.
There are exceptions. Unique or exceptional eyes may not be speshul at all, but make sense, if they are justified in some way. For instance:
- The character chose these eyes for him/herself. They may be contact lenses, false/prosthetic eyes for a blind character, or something else, but if the odd eye color is an aesthetic choice, then they cannot be considered a charge.
- The character didn't choose those eyes. It could be that a character has no option but to wear funny-looking eyes if they want to see at all. (Beware if this necessity is only brought up as an excuse to angst, however.)
- The character is a shapeshifter/has a mutable appearance and similarly chose for their eyes to be this way.
- This sort of eyes exists canonically.
- This sort of eyes is the result of a realistic negative trait, such as a birth defect, injury, or illness. An example would be the appearance of a character's pupils being washed out by severe cataracts.
- The character does not treat weird eyes as a positive trait, but addresses what life would be like if a character really and truly had freakish eyes (in other words, with application of good storytelling and thoughtful writing).