Domain: Healthcare — Human Physiology
Target concept: Pupillary Accommodation Reflex (Near Object)

Video generation prompt: A subject sits upright, first fixating on a distant target, then rapidly shifting the gaze to a finger held close to the eye. The camera is directed at and framed tightly on the eye throughout the movement. The procedure is simple, with clear eye movements and no extraneous background.

Evaluation guide:
(i) Target concept: Neural reflex arc linking retinal blur detection → pretectal nucleus → Edinger-Westphal nucleus → ciliary ganglion → sphincter pupillae & ciliary muscle contraction.
Minimum mechanism: Functional parasympathetic pathway must be intact; lens must be optically capable of accommodation; pupil musculature must be responsive; fixation must be voluntary and stable enough to trigger reflex.
(ii)Storyline: [Phase 1: Baseline] Subject fixates distant target → pupil dilated, lens flattened, distant target in focus, finger out-of-focus. [Phase 2: Trigger] Gaze initiates shift toward finger → transient saccade visible, pupil unchanged. [Phase 3: Response] Gaze stabilizes on finger → pupil constricts within ~200–300 ms, lens accommodates → finger sharpens, distant target blurs. [Perspective constraint] Camera fixed frontal view of one eye; no rotation; full eye (sclera, iris, pupil, limbus) continuously visible; finger enters frame from lateral side or is pre-positioned adjacent to eye without occluding it.

Manual:
Experimental Procedure
1. Subject sits upright, facing camera, eyes visible.
2. Subject first fixates on a clearly distant target (e.g., poster on wall).
3. Subject rapidly shifts gaze to their own index finger held close to the eye (within 15 cm, lateral to view).
Observation of Experimental Phenomena
- Eye moves smoothly from distant to near target.
- Pupil visibly constricts only during near fixation.
- Distant target appears blurred while finger appears sharp during near fixation.
Summary of Experimental Principles
- Pupillary Accommodation Reflex (Near Object): Parasympathetic activation causes sphincter pupillae contraction and ciliary muscle contraction → lens thickens + pupils constrict for near vision.

Prompt Grounding rubric:
level_1: No seated subject appears; neither a distant target nor a finger is shown; the eye is never brought into frame; there is no gaze-shift action of any kind.
level_2: A subject is present but is not seated upright (e.g., slouched, standing, or reclining); only one of the distant target or the near finger is shown, not both; the eye appears only in isolated glimpses rather than continuously; no clear shift from distant fixation to near fixation is depicted.
level_3: The subject sits upright; a distant target and a finger are both shown and are visually distinguishable from each other; the eye stays in frame for the whole clip; a gaze shift from the distant target toward the finger is visible as a head or eye movement, but the finger stops well short of the eye (e.g., held at arm's length or near mid-chest) instead of close to it.
level_4: The subject sits upright; the distant target is placed clearly far away (e.g., against a back wall) and the finger is brought visibly close to the eye; the eye remains fully in frame the entire time; the gaze shift proceeds as one clear, ordered transition from the distant target to the near finger; no unrelated objects or background movement compete for attention.
level_5: The subject sits upright; the distant target reads as unambiguously far (e.g., a poster on the far wall, out of focus relative to the eye) while the finger reads as unambiguously near (occupying the foreground beside the eye without covering it); the eye stays centered and fully visible for the whole clip; the gaze shift follows a single clean order (distant fixation first, then the finger comes into position, then the eye visibly turns toward it), with no back-and-forth, pause, or reversal of that order.

Scientific and Causal Correctness rubric:
level_1: The pupil shows no visible narrowing at any point; the finger and the distant target never trade places in apparent sharpness; the eye's appearance stays static throughout, with nothing that could be read as an accommodation response.
level_2: A pupil-size change or a sharpness change is present but only faintly or inconsistently, for example the pupil narrows slightly and briefly, or the finger looks only marginally sharper than the distant target with no matching pupil change, or vice versa; whichever cue is present does not clearly track the gaze shift.
level_3: Pupil constriction is clearly visible while the subject fixates the finger, and the finger visibly sharpens relative to the distant target; however the constriction's timing is loosely tied to the fixation, for instance it starts noticeably before the gaze reaches the finger, lags well behind it, or appears disconnected from the moment of fixation.
level_4: Pupil constriction is clearly visible and begins only after the gaze has settled on the finger, continuing for as long as the finger is fixated; the finger appears sharp and the distant target appears blurred specifically during this near-fixation interval; no constriction appears while the subject fixates the distant target.
level_5: Pupil constriction begins right as fixation on the finger stabilizes (not during the gaze transit itself), stays constricted for the whole near-fixation interval, and relaxes once fixation returns to the distant target or the clip ends; the sharpness relationship is unambiguous: the finger reads as sharp and the distant target reads as blurred only during the near-fixation window, with no premature or lingering constriction.

Spatiotemporal Consistency rubric:
level_1: The eye vanishes from frame and reappears, or the subject's head snaps to a new angle greater than 45 degrees with no in-between motion; the room lighting cuts or flares suddenly between frames; the finger or the distant target disappears mid-clip; the eye's anatomy visibly breaks (e.g., the pupil splits in two, or the iris warps out of its round shape).
level_2: The eye drifts more than about a third of the frame's width or height without smooth motion; the finger or the distant target jumps or flickers to a new position between frames instead of moving continuously; a shadow across the eye jumps abruptly instead of shifting gradually; the hand or head partly covers the eye with an abrupt cut rather than a gradual entry or exit.
level_3: The eye stays in frame the whole time and moves smoothly, without jumps; the finger and the distant target hold steady positions relative to the subject; the light source on the eye keeps the same apparent direction and brightness throughout; the eye's shape (sclera, iris, pupil, eyelid margin) stays intact; a single brief blink is acceptable.
level_4: The eye never touches the edge of the frame or gets cropped; the finger and the distant target stay put with no drift; the lighting on the eye and any cast shadow keep the same angle and softness across the whole clip; no blink or eyelid movement blocks the pupil or iris at any point; no motion blur obscures the pupil's edge.
level_5: The eye's position stays fixed at frame center, drifting no more than about 5% of the frame's width or height; the finger's position relative to the eye does not shift sideways or in apparent depth (no jump in perspective); the light and shadow on the eye keep an unchanging angle and softness for the entire clip; there is no visible flicker, stutter, or distortion of the iris or pupil's shape at any point.