Visual and Postural Behavior in Myopic and Non-Myopic Teenagers (CALYPSO)

Comportement Visuo-postural Des Adolescents Myopes et Non Myopes (CALYPSO)

The goal of this observational study is to learn whether different types of eyeglasses prescription and different types of lenses change how close teenagers hold objects when looking at them up close. The study includes adolescents who are non-myopic and adolescents who are myopic and wear either single-vision lenses or lenses slowing down myopia progression.

The main questions it aims to answer are:

Do teenagers in these three groups use different average working distances (eye-to-object distance) during everyday tasks?

Does wearing Essilor® Stellest® lenses change working distance compared with wearing single-vision lenses?

Researchers will compare the three groups to see if their working distances differ.

Participants will:

Complete an initial optometric eye examination.

Come for a second visit where they perform everyday activities while wearing a motion-capture system that measures how they move and how far they hold objects.

Study Overview

• Status: Recruiting
• Conditions: Myopia; Teenagers
• Intervention / Treatment: Device: Ophtalmic measurements; Behavioral: Visuo-postual measurements

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: David Rio, Phd; Phone Number: +33(0)155964840; Email: riod@essilor.fr
• Study Contact Backup: Name: Sébastien Fricker; Phone Number: +33155964970; Email: frickers@essilor.fr

Study Locations

• France
  • Paris, France, 75012
    • Recruiting
    • Paris Bastille
    • Contact: David Rio, Main investigator; Phone Number: +33(0)155964840; Email: riod@essilor.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Volunteer adolescent, fluent in French, able to follow protocol and read and write
• Aged between 12 and 17 years and 6 months
• Adolescent with no history, according to the participant and/or their legal representatives, of any pathology, deficit, or disorder that could interfere with visual or cognitive functions.
• If the subject wears glasses, they must have an ophthalmic prescription dated within the last year, certifying that a consultation was carried out during the previous year
• If the subject wears Essilor® Stellest® 1.0 lenses, they must have worn them for at least two (2) consecutive months prior to inclusion in the study.
• If the subject is nearsighted: -6.5D ≤ equivalent sphere ≤ -0.5D with usual correction
• If the subject is not nearsighted: -0.5 < equivalent sphere ≤ +2.5

Exclusion Criteria:

• Age ≤ 12 years
• Age > 17 years and 6 months
• Pregnant or breastfeeding women (Article L1121-5)
• Persons (legal representatives or subjects) deprived of their liberty by a judicial or administrative decision and persons hospitalized without consent pursuant to Articles L. 3212-1 and L. 3213-1 who are not covered by the provisions of Article L. 1121-8 and persons admitted to a health or social care facility for purposes other than research
• Participants who are currently excluded from another study
• All categories of persons who are particularly protected under French law are excluded from this research (Articles L1121-5 to L1121-9 of the Public Health Code)
• Declared neurological deficit, in particular a history of epileptic pathology or sensorimotor coordination disorders, vestibular or cerebellar pathology (e.g., balance disorders)
• Severe declared eye disease involving loss of visual field, such as glaucoma, involving loss of acuity and severe discomfort in low-light or overly bright environments, such as retinitis pigmentosa, or declared and treated dry eye syndrome.
• Gougerot-Sjögren syndrome or declared dry eye syndrome
• Declared aphakia or pseudophakia (intraocular implant)
• Declared systemic pathology, medical treatment, or medication with an effect on vision
• People with declared muscle paralysis
• Binocular vision problems such as amblyopia, strabismus, or nystagmus
• Children of employees or employees of Essilor International, Luxottica, GrandVision, and their subsidiaries
• Individuals who have undergone previous refractive surgery, have a history of strabismus surgery, or have a history of any type of eye surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: non-myopic teenagers	Device: Ophtalmic measurements; Participants will undergo a standard ophthalmic examination during the initial visit. All procedures are non-invasive, non-ionising, and conducted using devices routinely employed in clinical ophthalmic practice.; Behavioral: Visuo-postual measurements; The behavioral part of the study consists of a set of tasks designed to assess eye movements and visual behavior in both controlled and ecological conditions. Participants perform everyday activities while eye movements and body motion are recorded using an eye tracker and motion capture systems.
Experimental: myopic teenagers wearing Essilor® Stellest® lenses	Device: Ophtalmic measurements; Participants will undergo a standard ophthalmic examination during the initial visit. All procedures are non-invasive, non-ionising, and conducted using devices routinely employed in clinical ophthalmic practice.; Behavioral: Visuo-postual measurements; The behavioral part of the study consists of a set of tasks designed to assess eye movements and visual behavior in both controlled and ecological conditions. Participants perform everyday activities while eye movements and body motion are recorded using an eye tracker and motion capture systems.
Experimental: myopic teenagers wearing single vision lenses; Worn lenses do not have a myopia-control effect	Device: Ophtalmic measurements; Participants will undergo a standard ophthalmic examination during the initial visit. All procedures are non-invasive, non-ionising, and conducted using devices routinely employed in clinical ophthalmic practice.; Behavioral: Visuo-postual measurements; The behavioral part of the study consists of a set of tasks designed to assess eye movements and visual behavior in both controlled and ecological conditions. Participants perform everyday activities while eye movements and body motion are recorded using an eye tracker and motion capture systems.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Working distance using motion capture system	Quantitative assessment of working distance in meters during near vision tasks using a motion capture system	From enrollment to 3 months after enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gaze behavior during near vision tasks accessed with an eye-tracking system	Assessment of eye movements (spatial coordinates) during near vision tasks	From enrollment to 3 months after enrollment
Posture, eye-head coordination during near-vision tasks (with motion capture system)	Quantitative evaluation of postural behavior (spatial coordinates of body parts) while performing near vision tasks.	From enrollment to 3 months after enrollment
Correlation coefficient (R2) between optometric profile and near-vision behavior	Statistical analysis of the association between participants' optometric characteristics and their near vision behavioral patterns.	From enrollment to 3 months after enrollment

Collaborators and Investigators

• Sponsor: Essilor International

Study record dates

Study Major Dates

• Study Start (Estimated): April 3, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: February 12, 2026
• First Submitted That Met QC Criteria: February 23, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Myopia; Ophthalmological measurements
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia
• Other Study ID Numbers: WS10477; 2025-A02517-42 (Registry Identifier: ANSM RCB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No