Visual and Postural Behavior in Myopic and Non-Myopic Teenagers

Official title

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

Overview

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.

Interventions

• 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.

Primary outcome measures

• Working distance using motion capture system [Time frame: From enrollment to 3 months after enrollment]

Secondary outcome measures (3)

• Gaze behavior during near vision tasks accessed with an eye-tracking system [Time frame: From enrollment to 3 months after enrollment]
• Posture, eye-head coordination during near-vision tasks (with motion capture system) [Time frame: From enrollment to 3 months after enrollment]
• Correlation coefficient (R2) between optometric profile and near-vision behavior [Time frame: From enrollment to 3 months after enrollment]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

France · 1 center

• Paris Bastille — Paris

Identifiers

NCT: NCT07440134 · WS10477 · 2025-A02517-42

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗