Eye aspect ratio
How open your eyes are — vertical opening relative to eye width.
Why it matters
Eye openness signals alertness and youth; very low values can look tired or hooded.
What the eye aspect ratio captures
The eye aspect ratio describes how open your eye is: the vertical distance between the upper and lower lid margins divided by the width of the eye from corner to corner. A higher value means a rounder, more open aperture; a lower value means a narrower or more hooded opening. The tool measures both eyes and averages them.
Because it is a ratio of height to width, it captures shape rather than size. Two people with very different eye sizes can share the same aspect ratio if their eyes are equally open in proportion to their width.
Why openness reads the way it does
An open aperture tends to signal alertness and wakefulness, while a very low ratio can read as tired or heavily hooded. Hooding itself is an extremely common, normal feature that increases gradually with age as the upper-lid skin settles. Farkas 1994 provides the anthropometric grounding for treating lid opening relative to eye width as a measurable proportion.
The same ratio also underlies the everyday distinction between rounder eyes, which sit toward the higher end, and narrower or more almond-shaped eyes, which sit lower. Neither end is a defect; they are simply different eye shapes, each common and each suiting different faces. It is worth stressing that this metric describes a state as much as a structure, so the same eye can score quite differently from one photo to the next depending on how relaxed and rested you are.
Typical range, and why it is only a snapshot
The scored band runs from about 0.3 to 0.4, with a mesh average near 0.326. The single most important caveat is that this measurement is highly sensitive to expression and gaze: a squint, a smile, a yawn, tiredness or even bright light will narrow the opening and lower the value, while a wide, surprised look raises it.
For that reason the figure is best read as a snapshot of one moment rather than a fixed trait. If the value looks unusually low or high, check whether the photo caught you mid-blink, squinting against light, or smiling, and retake it with a calm, neutral, well-lit expression before drawing any conclusions.
Interpreting your number and what can change it
Because expression dominates this measurement, the most useful step is simply a rested, relaxed photo. Adequate sleep, managing any allergies or puffiness, and an un-squinted face all let the eyes sit at their natural opening, which is usually the fairest reading you can get for free.
Where genuine, persistent hooding from excess upper-lid skin is the concern, upper blepharoplasty is the surgical procedure that removes that skin to open the eye, and its results are permanent. It is mentioned here as a factual option only; it is a medical decision for a qualified surgeon, not something this report recommends.
Typical range
~0.3-0.4 (height : width)
Openness of the eye: vertical eyelid opening divided by eye width. Higher = rounder, lower = narrower.
What your reading means
- Typical
- Your eyes have an open, alert aperture.
- Less common
- Your eye openness is close to typical.
- Distinctive
- Your eye aperture reads relatively narrow or unusually wide (note: expression affects this).
How we measured it
We measure the vertical gap between upper and lower lids and divide by eye width (both eyes averaged).
The evidence
Sensitive to expression and gaze — a squint or smile changes it. Read as a snapshot, not a fixed trait.
References
- Farkas, L. G. (Ed.). (1994). Anthropometry of the Head and Face (2nd ed.). New York: Raven Press.