Pupil Near Response
Objective: This is a review article describing pupil responses, not a specific experimental protocol. The text discusses pupil near response (PNR) as a theoretical concept where pupils constrict in response to near fixation and accommodation, but does not present an original experimental methodology with specific procedures, equipment specifications, or data collection methods.
This is a Pupil Near Response protocol using Human as the model organism. The procedure involves 6 procedural steps, 1 equipment items. Extracted from a 2018 paper published in Journal of Cognition.
Model and subjects
Human
Study window
Estimated timing pending
Core workflow
Stimulus presentation setup • Dark period • Measure pupil response latency
Primary readouts
- Pupil size as a proportion of pre-stimulus pupil size
- Latency period duration (0-0.2s)
- Constriction rate and magnitude (0.2-1.5s)
- Sustained constriction vs. pupil escape (1.5-10s)
Key equipment and reagents
Verified items
0
Direct vendor links
0
Use this page as an execution guide, then fall back to the source paper whenever you need exact exclusions, dosing details, or assay-specific caveats.
Confirm first
- Verify the animal model, intervention setup, and collection timepoints against the source paper.
- Check that every direct vendor link matches the exact specification your lab plans to run.
Use the page like this
- Work through the protocol steps in order and use the inline vendor chips only when you need to source or verify an item.
- Jump to Experimental Context for readouts, data shape, and analysis flow before planning downstream analysis.
Protocol Steps
Start here. The step list is optimized for running the experiment, with direct vendor links available inline when you need to source a cited item.
Stimulus presentation setup
Present visual stimuli on a computer monitor consisting of full-screen colors (blue or red light)
Note: The text describes a typical pupil light response (PLR) protocol as an example, not a specific near response protocol
View evidence from paper
“Figure 4 shows a typical PLR, elicited by 10 s of blue or red light presented on a computer monitor, followed by 20 s of a dark screen”
Dark period
Present a dark screen following the light stimulus
Note: This allows measurement of pupil recovery/dilation
View evidence from paper
“10 s of blue or red light presented on a computer monitor, followed by 20 s of a dark screen”
Measure pupil response latency
Record the latency period during which the pupil does not yet respond to light stimulus onset
Note: Latency depends on stimulus intensity and age
View evidence from paper
“0–0.2s: This is the latency period during which the pupil does not yet respond. The exact latency depends on many factors, such as stimulus intensity (latencies decrease with stimulus intensity) and age (latencies increase with age)”
Measure pupil constriction phase
Record rapid pupil constriction until minimum size is reached
Note: This phase represents the initial constriction response
View evidence from paper
“0.2–1.5s: The pupil constricts strongly and rapidly until it reaches its minimum size”
Measure sustained constriction or pupil escape
Record whether pupil remains fully constricted or shows unconstriction (redilation). Note that blue light leads to sustained constriction while red light leads to pupil escape
Note: Pupil escape occurs with red light but not blue light due to different photoreceptor sensitivities
View evidence from paper
“1.5–10s: The pupil either remains fully constricted while the light remains on, or unconstricts (redilates) slightly. This unconstriction, when it occurs, is sometimes called pupil escape; whether it occurs depends on the color of the light: blue light leads to sustained constriction, whereas red light leads to pupil escape”
Measure pupil recovery/dilation
Record gradual pupil recovery to original size following light offset
Note: Recovery is slower than constriction and is faster for red than blue light. After high-intensity blue light, pupil may remain slightly constricted for many minutes (post-illumination pupil response)
View evidence from paper
“10 s–30s: The pupil gradually recovers to its original size. Dilation due to light offset occurs much more slowly than constriction due to light onset”