pupil
Enable an AI agent to recognise an anatomical pupil, record its appearance and response under known conditions, and judge whether comparison, further observation or authorised assessment is warranted.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise an anatomical pupil, record its appearance and response under known conditions, and judge whether comparison, further observation or authorised assessment is warranted.
The pupil is the central aperture of the iris that admits light to the retina, its diameter being set by the opposing action of the sphincter and dilator pupillae under autonomic and light-reflex control.
It can be Locate and label the pupil in an eye observation while retaining uncertain boundaries.; Measure aperture geometry using a stated calibration and method.; Compare pupil observations across time or between eyes under matched conditions.; Record responses during an authorised observation protocol, including which eye received the stimulus.; Request a clearer or better controlled observation when visibility or context is inadequate.; Flag a documented change for qualified assessment under an applicable protocol without inferring its cause..
Distinguishing features
Identify an aperture bounded by the iris rather than labelling the entire coloured iris as the pupil.
Distinguish the aperture boundary from reflections, shadows or dark regions elsewhere in an eye image.
Distinguish the physical aperture from its apparent image through the eye's optics; record which representation was measured.
Associate the structure with an anatomical eye; references to educational roles or instrument apertures require a different interpretation.
Scope
+ Identification of the pupil and its association with a particular eye
+ Pupillary boundary, size, shape and position within the iris
+ Changes in aperture under recorded illumination and viewing conditions
+ Comparison with the fellow pupil and previous observations
+ Observation quality and constraints on pupil measurement or testing
- A pupil meaning a learner or student
- The iris as tissue, including its pigmentation and structural condition
- Whole-eye anatomy, visual acuity and refractive performance
- Retinal, optic nerve and neurological conditions as independently modelled entities
- Medication administration, diagnosis and treatment planning
- Entrance and exit pupils of optical instruments
Characteristics
- Eye association
- Containing eye reference; subject-relative left, right or unresolved Prevents observations from different eyes or subjects being combined.
- Observed aperture size
- Diameter or specified axis lengths in mm; pixels only when uncalibrated Supports comparison while preserving the distinction between physical estimates and image measurements.
- Boundary shape
- Round, oval, slit-like, irregular, other described or indeterminate Avoids assuming that every pupil is circular or adequately described by one diameter.
- Aperture position
- Centre offset in mm or normalised coordinates relative to a named iris landmark Allows position changes to be distinguished from changes in camera viewpoint or gaze.
- Illumination context
- Illuminance in lux where available, with measurement location; otherwise described lighting Makes size and response observations interpretable in their lighting context.
- Observed response
- Constriction observed, dilation observed, no change detected, indeterminate or not tested; stimulus and interval required Separates recorded behaviour from an unsupported conclusion about pupil function.
- Response timing
- Latency and observation duration in ms or s, with temporal resolution Shows whether the recording could resolve the response being described.
- Inter-eye size difference
- Signed difference in mm using a declared eye order and matched conditions Makes asymmetry explicit without assigning a cause or clinical significance.
- Boundary visibility
- Fully visible, partly obscured, not visible or uncertain; obstruction described Prevents poor visibility from being mistaken for an absent or unusually shaped pupil.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 16 findings · 26 questions.
Pupil identity and boundary Establishes which anatomical aperture is represented and where its boundary lies.
An agent must distinguish the pupil from surrounding tissue, imaging artefacts and other meanings of the name.
Anatomical referent
Connects the pupil to its containing eye and the organism context.
Eye-linked aperture
Record evidence that the target is an iris-bounded aperture, together with eye identity and unresolved classification.
- What observation establishes that this target is the pupil of an anatomical eye? definition
- Which subject, species and subject-relative eye does the observation concern? provenance
Aperture delimitation
Separates the pupil opening from iris tissue and the optical appearance used to observe it.
Supported pupil boundary
Record the visible iris edge, uncertain segments and whether the boundary is an image observation or a reconstructed physical estimate.
- Which portions of the proposed boundary are supported by a visible iris edge rather than shadow, reflection or occlusion? boundary
- Does this outline describe the apparent pupil in an image or an estimate of the physical aperture? definition
Aperture geometry Records pupil size, shape and position using methods appropriate to the observed aperture.
A single diameter can conceal irregular shape, viewpoint distortion or uncertain scale.
Size and contour
Describes the opening without presuming circular geometry.
Calibrated aperture description
Record diameter, axes, area or contour as appropriate, preserving calibration and estimation uncertainty.
- Which dimensions or contour representation adequately describe this pupil's observed shape? measurement
- What scale calibration and uncertainty support the reported dimensions? measurement
Position and viewpoint
Locates the aperture relative to the iris while accounting for observation angle.
Referenced aperture position
Record pupil position against a named anatomical reference and retain gaze or camera-angle limitations.
- Relative to which iris landmark or coordinate system is the pupil centre located? measurement
- Could gaze direction or camera angle explain the apparent offset or elongation? boundary
Pupillary response Records aperture changes in relation to documented illumination or viewing events.
Pupil behaviour cannot be interpreted from size alone or from a stimulus whose timing and target are unknown.
Stimulus and baseline
Establishes the conditions before and during a response observation.
Documented response conditions
Record baseline lighting, adaptation interval, viewing target and the event against which change is assessed.
- What lighting, adaptation interval and viewing distance preceded the observation? provenance
- What stimulus or viewing change occurred, when did it occur and which eye received it? provenance
Response course
Captures the direction, extent and timing of observed aperture change.
Observed change sequence
Record the measured response of the observed eye, distinguishing an undetected change from an inadequately observed response.
- How did pupil size change over the recorded interval, and what latency or amplitude can the measurement resolve? measurement
- Was the observed pupil in the stimulated eye or the fellow eye, and were both eyes recorded? provenance
- If no change was detected, were visibility, stimulus documentation and sampling sufficient to support that statement? boundary
Comparison and observation decisions Supports defensible comparisons and determines what further pupil observation is justified.
Apparent asymmetry or change must be separated from mismatched conditions before an agent acts on it.
Paired and longitudinal comparison
Compares pupils across eyes or time with explicit limits on comparability.
Condition-matched difference
Record the direction and magnitude of differences alongside timing, lighting and method compatibility.
- What size, shape or response difference is observed between the two eyes or against a previous observation? measurement
- Were lighting, viewing target, measurement method and observation timing sufficiently matched for this comparison? boundary
Observation limits and next actions
Links evidence quality and pupil-specific context to permitted follow-up.
Qualified pupil assessment
Record visibility limits, relevant reported exposures or eye procedures, and the authority governing repeat observation or referral.
- Which occlusions, reflections, reported eye drops or prior eye procedures could limit interpretation of this observation? provenance
- Does the evidence support comparison, require a repeat measurement or meet an applicable criterion for qualified assessment? action
- What authorisation and protocol govern any further light-response testing or other intervention involving this eye? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- physiologic (light-responsive) pupil
- anisocoric pupil (unequal diameters)
- miotic pupil
- mydriatic pupil
- relative afferent pupillary defect (Marcus Gunn pupil)
- tonic (Adie) pupil
- Argyll Robertson pupil
- Horner (oculosympathetic) pupil
- Which of these kinds and varieties hold for the sense of pupil this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q10768 - Anatomical pupil of the eye; not the student sense
- FMA - 58252 - Foundational Model of Anatomy: Pupil
- UBERON - UBERON:0001771 - uberon pupil
- MeSH - D011680 - Pupils
- SNOMED CT - 392406005 - Pupil structure (body structure)
- Which of these identifiers and schemes hold for the sense of pupil this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- ISO 15004-2 (Ophthalmic instruments - Fundamental requirements and test methods - Light hazard protection), International Organization for Standardization - photic-safety calculations use a 7 mm dilated pupil as the conservative entrance-pupil diameter
- CIE / ISO 11664 series and related photometric practice - luminous quantities at the eye are referred to the entrance pupil
- Clinical documentation of pupil size and reactivity is governed by local medical-record and emergency-care protocols (e.g. GCS eye-opening and PERRLA charting), not by a single global product standard
- Which of these standards and regulation hold for the sense of pupil this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Bedside and emergency neurological examination: size, symmetry, and light reactivity (PERRLA) as a window on midbrain and cranial-nerve function
- Ophthalmology and optometry: entrance pupil for refraction, intraocular-lens calculation, and imaging (fundus photography, OCT, perimetry)
- Pharmacology: miotics and mydriatics used to constrict or dilate the pupil for examination, surgery, or glaucoma therapy
- Optics and photography: the eye's entrance pupil sets retinal illuminance and depth of field; camera and VR/AR optical designs match or assume a human pupil diameter
- Forensic and occupational: pupil size under drugs, toxins, or workplace lighting as a clinical or safety sign
- Which of these real-world use hold for the sense of pupil this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- resting diameter in typical indoor light - 2-4 - mm
- diameter in darkness (maximal physiologic dilation) - 4-8 (rarely to ~9 in young adults) - mm
- diameter under bright light (miosis) - 1-2 - mm
- anisocoria regarded as physiologic when isolated and stable - ≤0.4-0.5 - mm
- latency of the direct light reflex - 0.2-0.5 - s
- Which of these typical measurements hold for the sense of pupil this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Fixed dilated pupil after trauma or herniation - neurosurgical emergency when new and unilateral with declining consciousness
- Pharmacologic mydriasis or miosis mimicking nerve palsy or intoxication
- Relative afferent pupillary defect indicating asymmetric optic-nerve or severe retinal disease
- Acute angle-closure glaucoma precipitated by mid-dilated pupil in anatomically predisposed eyes
- Phototoxicity and glare when a large pupil admits excess light (post-mydriasis, traumatic iris sphincter tear)
- Surgical or traumatic iris damage producing a permanently irregular or atonic pupil with glare and reduced acuity
- Which of these failure modes and hazards hold for the sense of pupil this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- English 'pupil' is also the school-enrolment term (especially UK/Commonwealth); anatomical use is unambiguous in clinical contexts but collides in general registries
- Named eponyms (Argyll Robertson, Adie, Horner, Marcus Gunn) are used worldwide in neurology; some jurisdictions prefer descriptive terms (e.g. 'light-near dissociation', 'tonic pupil', 'oculosympathetic palsy')
- Pharmacologic mydriatic combinations and legal constraints on topical agents (e.g. atropine, tropicamide) vary by national formulary
- Which of these regional variation hold for the sense of pupil this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- iris - The iris is the contractile pigmented diaphragm; the pupil is the aperture it forms, not a separate tissue
- entrance pupil (optics) - The optical entrance pupil is the image of the anatomical pupil as seen through the cornea; it is slightly magnified and is the quantity used in photometry and instrument design
- pupil of a student / school pupil - Homonym: a person enrolled in education (Wikidata Q1344284 and related), not an ocular aperture
- artificial / prosthetic pupil or pinhole - An implanted or external aperture (iris prosthesis, pinhole occluder) that substitutes for the natural pupil rather than being it
- coloboma or iridectomy opening - A structural defect or surgical gap in the iris that may enlarge or distort the true pupillary margin rather than being a physiologic pupil
- Which of these neighbouring kinds and how to tell them apart hold for the sense of pupil this model covers, and on what evidence? provenance
Sources
- The Pupil: Anatomy, Physiology, Abnormalities, and Clinical Testing - Clinical anatomy, light-reflex testing, and named pathologic pupil types used in practice
- Anatomy, Head and Neck: Eye Pupil - Anatomical definition, sphincter/dilator innervation, and typical adult diameter range
- pupil (Q10768) - Canonical identifier and distinction from the educational-enrolment sense of 'pupil'
What the second pass must settle
- Does vr.tr.pupil denote the anatomical pupil, and is its intended coverage human-only or inclusive of other species?
- Does an existing Vercy eye or anatomical-aperture model already own this concept, requiring a link instead of a separate publication?
- Which measurement conventions should distinguish the physical aperture from its apparent optical image across supported devices?
- Which species-, age- and context-specific evidence should govern interpretation of pupil geometry, inter-eye differences and response measurements?
- Which sourced protocols define permitted observation methods and thresholds for repeat measurement or qualified assessment?