Search research articles

Related Concept Videos

Photoreceptors and Visual Pathways

Photoreceptors and Visual Pathways

At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

A Case Report of Proximal Radioulnar Osteosarcoma in a Great Dane Dog.

Case reports in veterinary medicine·2026

Same author

Job satisfaction among local-level health workers following decentralization in Nepal.

BMC health services research·2026

Same author

Influence of parenting style on the self-esteem of adolescents and the factors associated with low self-esteem: An institutional based cross-sectional study in Tokha municipality, Nepal.

PloS one·2026

Same author

Assessment of drug-related problems and associated factors among patients with chronic obstructive pulmonary disease in Dailekh, Nepal: a cross-sectional study.

Scientific reports·2026

Same author

Contrast sensitivity and functional aspects of cone, rod, and melanopsin vision in humans.

Handbook of clinical neurology·2026

Same author

The Feasibility of Combining Focused Ultrasound and Copper-Cystine Biohybrid for Diabetic Wound Healing.

Ultrasound in medicine & biology·2026

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Search research articles

Related Experiment Video

Updated: Apr 10, 2026

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Published on: November 26, 2019

The Post-Illumination Pupil Response (PIPR).

Prakash Adhikari¹, Andrew J Zele¹, Beatrix Feigl²

¹Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.

Investigative Ophthalmology & Visual Science

|June 13, 2015

Summary

This study characterizes the spectral sensitivity and optimal measurement protocols for the post-illumination pupil response (PIPR), revealing that plateau and 6-second metrics are most reliable for assessing melanopsin function. The findings provide a basis for disease monitoring using PIPR.

More Related Videos

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy

Published on: April 11, 2019

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Published on: February 15, 2022

Related Experiment Videos

Last Updated: Apr 10, 2026

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation

Published on: November 26, 2019

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy

Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy

Published on: April 11, 2019

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Published on: February 15, 2022

Area of Science:

Ophthalmology
Neuroscience
Photobiology

Background:

The post-illumination pupil response (PIPR) is a measure of the intrinsic melanopsin photoresponse.
Quantification of PIPR has relied on four metrics, but only one's spectral sensitivity was previously known.

Purpose of the Study:

To determine the spectral sensitivity of the remaining three PIPR metrics.
To optimize human PIPR measurement by identifying the protocol yielding the largest response, optimal duration, and metrics with the lowest coefficient of variation.

Main Methods:

Pupil light reflex (PLR) measured using a Maxwellian view pupillometer.
Spectral sensitivity of four PIPR metrics assessed using 1-second light pulses.
PLR measured across varying stimulus durations, irradiances, and wavelengths (465 nm and 637 nm) to determine optimal measurement parameters.

Main Results:

The melanopsin photopigment nomogram accurately describes the spectral sensitivity of all four PIPR metrics.
PIPR amplitude was maximal with short-duration (1-second), short-wavelength (465 nm) pulses at high irradiance.
Plateau and 6-second PIPR metrics exhibited the lowest intra- and interindividual coefficients of variation (≤ 0.2).

Conclusions:

All PIPR metrics directly measure melanopsin photoresponse.
Recommended protocol for disease monitoring involves short-duration pulses (≤ 1 second) with high melanopsin excitation, analyzed using plateau and/or 6-second metrics.
Established PIPR duration data can inform interstimulus interval selection in clinical testing.