--- title: neos® quantitative pupillometry description: neos® provides objective, quantitative pupillometry, including the RAPD neoscore, from an automated swinging flashlight test, delivering clinically meaningful measurements for the afferent and efferent visual system. image: https://www.machinemd.com/hubfs/Lara%20Varjo.png --- [![MachineMD_RGB_C_BrightBG](https://www.machinemd.com/hubfs/MachineMD_RGB_C_BrightBG.svg "MachineMD_RGB_C_BrightBG")](https://www.machinemd.com?hsLang=en) - [neos](https://www.machinemd.com/neos) - [pupillometry](https://www.machinemd.com/neos/quantitative-pupillometry) - [ocular alignment](https://www.machinemd.com/neos/ocular-alignment) - [science](https://www.machinemd.com/science) - [oculometrics](https://www.machinemd.com/oculometrics) - [Multiple Sclerosis](https://www.machinemd.com/multiple-sclerosis) - [Myasthenia Gravis](https://www.machinemd.com/myasthenia-gravis) - [Huntington's Disease](https://www.machinemd.com/huntingtons-disease) - [Parkinson's Disease](https://www.machinemd.com/parkinsons-disease) - 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[Parkinson's Disease](https://www.machinemd.com/parkinsons-disease) - [Progressive Supranuclear Palsy](https://www.machinemd.com/progressive-supranuclear-palsy) - [Alzheimer's Disease](https://www.machinemd.com/alzheimers-disease) - [Brain Tumors](https://www.machinemd.com/brain-tumors) - [Stroke](https://www.machinemd.com/stroke) - [Traumatic Brain Injury](https://www.machinemd.com/traumatic-brain-injury) - [Niemann Pick Type C](https://www.machinemd.com/niemann-pick-type-c) - [Gaucher Disease](https://www.machinemd.com/gaucher-disease) - [NAION](https://www.machinemd.com/naion) - [Idiopathic Intracranial Hypertension](https://www.machinemd.com/idiopathic-intracranial-hypertension) - [about](https://www.machinemd.com/about) - [news](https://www.machinemd.com/news) - [contact](https://www.machinemd.com/contact) [LinkedIn](https://www.linkedin.com/company/machinemd/) [Follow us on Facebook](https://twitter.com/md_machine) ![machineMD-neos4-1](https://www.machinemd.com/hs-fs/hubfs/machineMD-neos4-1.jpg?width=2000&height=1125&name=machineMD-neos4-1.jpg "machineMD-neos4-1") ![neos_r_Logo_neg](https://www.machinemd.com/hs-fs/hubfs/neos_r_Logo_neg.png?width=564&height=138&name=neos_r_Logo_neg.png) # Quantitative Pupillometry neos® binocular pupillometer provides an objective assessment of pupil responses, including measurements of efferent pupillary function and an automated swinging flashlight test ## Measuring RAPD - the easy way Detect the unseen. Helping you make data-driven decisions. ![rapd neoscore -62](https://www.machinemd.com/hubfs/rapd%20neoscore%20-62.png "rapd neoscore -62") The **RAPD** ne**o**score™ enables ne**o**s® to provide quantified results based on objective tests, supporting the analysis of relative afferent pupillary defects. Keep reading to find out what it means and why it matters. ## Automating the swinging flashlight test Manual swinging flashlight tests only correctly estimate 40% of RAPD magnitudes2. Automated testing of RAPD using a VR-headset and eye-tracking reaches non-inferior performance compared with assessment by senior neuro-ophthalmologists3. Quantitative pupillometry can therefore provide reliable measurements with a low error rate, assessing variables including pupil size, constriction amplitude, and response latency. ne**o**s® uses an automated, digitalized version of the swinging flashlight test: simultaneously measuring direct and consensual pupil responses with a period of 3 seconds. 2Boucher T, Fortin É, Evoy F. The standard swinging flashlight test: reliable or not (P1.9-009). Neurology. 2019; 92(15 Supplement): P1.9–009. 3[https://www.machinemd.com/news/study-shows-great-potential-to-automate-quantitative-pupillometric-tests](https://www.machinemd.com/news/study-shows-great-potential-to-automate-quantitative-pupillometric-tests?hsLang=en) Three Scenarios. Clear Results Whether an RAPD is present in the right eye, left eye, or not at all — the measurement results are clear, data-driven, and easy to interpret. On the right, we showcase three typical measurement scenarios demonstrating the performance of the RAPD ne**o**score™ algorithm. ![Right RAPD](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/Right%20RAPD.png?width=1200&length=1200&name=Right%20RAPD.png) ![Left RAPD](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/Left%20RAPD.png?width=1200&length=1200&name=Left%20RAPD.png) ![no RAPD](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/no%20RAPD.png?width=1200&length=1200&name=no%20RAPD.png) ## Efferent pupillary function  neos® systematically presents visual stimuli to both eyes individually and together, measuring the resulting eye movements and pupillary changes of each eye, and charting this data in an examination report. Efferent pupillary function can be assessed quickly, reliably, and objectively in an immersive VR environment with neos®. The head-mounted display minimizes the influence of ambient light, removing the need to darken an examination room. neos® continuously measures the pupil size of both eyes in real-time with high precision. This sequence is repeated to ensure consistent and meaningful results. ![exam_step_4_efferent copy](https://www.machinemd.com/hs-fs/hubfs/exam_step_4_efferent%20copy.jpg?width=1200&length=1200&name=exam_step_4_efferent%20copy.jpg) Pupillography helps to quickly appreciate pupil dynamics in addition to measurement values Conference presentation ### Acute Horner Syndrome identified by Pupillography revealing Internal Carotid Artery Dissection Victoria Borisova, Muriel Dysli European Neuro-Ophthalmology Society (EUNOS) Meeting, 2026 doi: [10.1080/01658107.2026.2651025View publication](https://www.tandfonline.com/doi/full/10.1080/01658107.2026.2651025#s0021) Study details ![EUNOS_Horner_2026](https://www.machinemd.com/hubfs/EUNOS_Muriel.png) Click to enlarge **Introduction** Acute anisocoria with ipsilateral ptosis, particularly when the pupillary asymmetry is greater in the dark, should raise suspicion for Horner syndrome and prompt urgent evaluation for potentially life-threatening causes such as internal carotid artery (ICA) dissection. Early recognition in the neuro-ophthalmology setting is critical to prevent cerebral ischemic complications. **Case Report** - A 38-year-old woman presented with a smaller right pupil and mild right ptosis for 5 days, accompanied by right neck pain and facial pressure. She had recently been physically active. Exam showed right miosis (more pronounced in dim light) with briskly reactive pupils and mild ptosis. - Pupillography ([neos](https://www.machinemd.com/neos/quantitative-pupillometry?hsLang=en)® system) demonstrated a clear right-sided dilatation lag, providing objective confirmation of oculosympathetic dysfunction. Pharmacological testing for Horner syndrome was not pursued because the lopidine test could not be realiably interpreted in cases of recent onset. ![](https://www.machinemd.com/hs-fs/hubfs/image-png-3.png?width=324&height=370&name=image-png-3.png) - Contrast-enhanced computed tomography (CT) of the head and CT angiography (CTA) revealed a short-segment mural hematoma consistent with right ICA dissection, extending from the distal cervical segment to the transition into the petrous segment. No intracranial hemorrhage or cerebral ischemia was detected. ![](https://www.machinemd.com/hs-fs/hubfs/image-png-4.png?width=790&height=532&name=image-png-4.png) **Management** - The patient was admitted for monitoring and started on antiplatelet therapy with Aspirin 100mg. - Cervical artery duplex ultrasound showed no significant stenosis - With no signs of connective tissue disorder and a history of intense physical activity, the dissection was considered likely provoked. - MR angiography (MRA) at 6-month follow-up showed normalization of the vessel lumen. ![](https://www.machinemd.com/hs-fs/hubfs/image-png-Jun-09-2026-09-19-09-3182-AM.png?width=793&height=456&name=image-png-Jun-09-2026-09-19-09-3182-AM.png) **Discussion** - Acute Horner syndrome with ipsilateral neck/facial pain is a classic red flag for ICA dissection. - As pupillary findings may be subtle, objective testing (e.g., pupillography) can support clinical suspicion, expedite emergency imaging, and occasionally a pharmacologic testing is not necessary any more due to the characteristic appearance with dilation lag in pupillography. - Prompt vascular imaging with CTA or MRA is essential for diagnosis. - Early antithrombotic therapy (antiplatelet or anticoagulaton, depending on clinical context) reduces thromboembolic and ischemic risk. - Painful acute Horner syndrome should be treated as an emergency until ICA dissection is excluded. ## neos gives confidence assessing pupils .. in support of clinical decision making due to reliable data. ... by supporting smoother workflows and helping reduce the chance of errors in daily operations. ... in support of identifying signs early, reducing uncertainty for both clinicians and patients and enabling faster interventions.   … in easier tracking, monitoring, and comparison of results over time, ensuring consistent and reliable documentation.   ... in easy adoption across teams, enhancing accessibility and ensuring smooth integration into diverse clinical settings.   … in reliable documentation and streamlined workflows, ensuring future-proof operations with seamless cloud-based solutions. Dive into our latest studies and market research.   [Discover the science](https://www.machinemd.com/news/study-shows-great-potential-to-automate-quantitative-pupillometric-tests?hsLang=en) In addition to quantitative pupillometry, neos® provides a comprehensive assessment of eye alignment, eye movements, and more.   [Learn more](https://www.machinemd.com/neos?hsLang=en) machineMD is proud to work with clinical partners around the world, including [![20cd007_logo_dxp_usz](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/20cd007_logo_dxp_usz.jpg?width=1200&length=1200&name=20cd007_logo_dxp_usz.jpg)](https://www.usz.ch/fachbereich/augenklinik/angebot/neuroophthalmologie/) ![USC-Roski-logo-1200x600-1-1024x512](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/USC-Roski-logo-1200x600-1-1024x512.jpg?width=1200&length=1200&name=USC-Roski-logo-1200x600-1-1024x512.jpg) ![WEH_Hospital_Logo-horizontal-Maraschino-copy](https://19556649.fs1.hubspotusercontent-na1.net/hub/19556649/hubfs/WEH_Hospital_Logo-horizontal-Maraschino-copy.png?width=1200&length=1200&name=WEH_Hospital_Logo-horizontal-Maraschino-copy.png) [![bochum](https://www.machinemd.com/hs-fs/hubfs/bochum-1.png?width=1200&length=1200&name=bochum-1.png)](https://www.klinikum-bochum.de/fachbereiche/neurologie/fachbereich.html) [![Inselspital](https://www.machinemd.com/hs-fs/hubfs/1280px-Inselspital.png?width=1200&length=1200&name=1280px-Inselspital.png)](https://www.insel.ch/) [![LUKS](https://www.machinemd.com/hs-fs/hubfs/LUKS.png?width=1200&length=1200&name=LUKS.png)](https://www.luks.ch/) Get started with neos® ##### SWITZERLAND Our partners at Von Hoff AG are ready to help you get started with neos®  in Switzerland. [Learn more](https://www.vonhoff.ch/artikel/machinemd_neos/) [![Von-Hoff-Logo](https://www.machinemd.com/hs-fs/hubfs/Von-Hoff-Logo.png?width=190&height=47&name=Von-Hoff-Logo.png "Von-Hoff-Logo")](https://www.vonhoff.ch/artikel/machinemd_neos/) ##### Europe neos® is certified as a Class IIa medical device under the EU-MDR, and registered with the MHRA in the UK.  [Contact Us](https://www.machinemd.com/neos/quantitative-pupillometry#contact_us) ##### USA neos® is a Class I medical device registered in the US. Our team at machineMD Inc. is based in Boston, MA. . [Contact Us](https://www.machinemd.com/neos/quantitative-pupillometry#contact_us) ### Contact Us For all other markets, and to find out more about research collaborations with machineMD, please complete the below form: ![MachineMD_RGB_C_DarkBG\[5718\]](https://www.machinemd.com/hs-fs/hubfs/MachineMD_RGB_C_DarkBG%5B5718%5D.png?width=200&height=26&name=MachineMD_RGB_C_DarkBG%5B5718%5D.png "MachineMD_RGB_C_DarkBG[5718]") [career](https://www.machinemd.com/career?hsLang=en) [certifications](https://www.machinemd.com/quality-policy?hsLang=en) [imprint and privacy policy](https://www.machinemd.com/imprint?hsLang=en) [Follow us on LinkedIn](https://www.linkedin.com/company/machinemd) ![](https://f.hubspotusercontent00.net/hubfs/7712601/back-to-top.png) © machineMD AG 2026 | All rights reserved. ```json { "@context" : "https://schema.org", "@type" : "ScholarlyArticle", "abstract" : "Introduction Acute anisocoria with ipsilateral ptosis, particularly when the pupillary asymmetry is greater in the dark, should raise suspicion for Horner syndrome and prompt urgent evaluation for potentially life-threatening causes such as internal carotid artery (ICA) dissection. Early recognition in the neuro-ophthalmology setting is critical to prevent cerebral ischemic complications. Case Report A 38-year-old woman presented with a smaller right pupil and mild right ptosis for 5 days, accompanied by right neck pain and facial pressure. She had recently been physically active. Exam showed right miosis (more pronounced in dim light) with briskly reactive pupils and mild ptosis. Pupillography (neos® system) demonstrated a clear right-sided dilatation lag, providing objective confirmation of oculosympathetic dysfunction. Pharmacological testing for Horner syndrome was not pursued becaus", "author" : [ { "@type" : "Person", "name" : "Victoria Borisova" }, { "@type" : "Person", "name" : "Muriel Dysli" } ], "datePublished" : "2026", "description" : "Introduction Acute anisocoria with ipsilateral ptosis, particularly when the pupillary asymmetry is greater in the dark, should raise suspicion for Horner syndrome and prompt urgent evaluation for potentially life-threatening causes such as internal carotid artery (ICA) dissection. Early recognition", "headline" : "Acute Horner Syndrome identified by Pupillography revealing Internal Carotid Artery Dissection", "image" : "https://19556649.fs1.hubspotusercontent-na1.net/hubfs/19556649/EUNOS_Muriel.png", "inLanguage" : "en", "isPartOf" : { "@type" : "CreativeWork", "name" : "European Neuro-Ophthalmology Society (EUNOS) Meeting, 2026" }, "name" : "Acute Horner Syndrome identified by Pupillography revealing Internal Carotid Artery Dissection", "publisher" : { "@id" : "https://www.machinemd.com/#organization", "@type" : "Organization", "name" : "machineMD", "url" : "https://www.machinemd.com" }, "sameAs" : "https://www.tandfonline.com/doi/full/10.1080/01658107.2026.2651025#s0021", "url" : "https://www.tandfonline.com/doi/full/10.1080/01658107.2026.2651025#s0021" } ``` ```json { "@context" : "https://schema.org", "@type" : "MedicalDevice", "alternateName" : "neos", "brand" : { "@type" : "Brand", "name" : "machineMD" }, "category" : "Ophthalmology | Neurology", "description" : "Automated, standardized quantitative pupillometry including the RAPD neoscore from an automated swinging flashlight test.", "deviceClass" : [ "EU: Class IIa", "UK: Class IIa", "CH: Class IIa", "US: Class I" ], "isAccessoryOrSparePartFor" : "Neuro-ophthalmic examination", "manufacturer" : { "@type" : "Organization", "address" : { "@type" : "PostalAddress", "addressCountry" : "Switzerland", "addressLocality" : "Bern" }, "name" : "machineMD AG" }, "name" : "neos®", "purpose" : "Provides objective measurements of afferent and efferent pupillary function; supports diagnosis and monitoring in EU/CH/UK.", "url" : "https://www.machinemd.com/neos/quantitative-pupillometry" } ``` ```json { "@context" : "https://schema.org", "@type" : "FAQPage", "mainEntity" : [ { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "neos® measures afferent and efferent pupillary function using standardized stimuli and reports quantitative parameters, including an RAPD neoscore derived from an automated swinging flashlight test." }, "name" : "What does quantitative pupillometry with neos® measure?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "neos® quantitative binocular pupillometry runs an automated test sequence in under three minutes." }, "name" : "How long does quantitative pupillometry take?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "neos® is intended to be used by health care professionals in clinical settings (e.g., ophthalmology, optometry, neurology). In the EU/CH/UK, neos® results support diagnosis and monitoring; in the US, neos® provides objective, quantitative measurements." }, "name" : "Who is intended to use neos®?" } ] } ```