Oculomotor Response While Using a Helmet Display Incorporating an Accommodation-vergence Stress Reduction Algorithm

Visual Fatigue Clinical Trial

— ALGO-HMD  

Official title:

Oculomotor Response While Using a Helmet Display Incorporating an Accommodation-vergence Stress Reduction Algorithm

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05243277
• Other study ID #: 2021PBMD04
• Secondary ID: 2021-A02286-35
• Status: Recruiting
• Start date: March 16, 2023
• Est. completion date: December 16, 2024

Study information

• Verified date: March 2023
• Source: Direction Centrale du Service de Santé des Armées
• Contact: Pascaline NEVEU, PhD
• Phone: 178651212
• Email: pascaline.neveu[@]intradef.gouv.fr
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Operational military personnel are increasingly using virtual or augmented reality headsets in the field or in training. However, these devices cause a conflict between accommodation (focus to see clearly) and vergence (alignment of both eyes on the object being viewed) that can be a source of visual fatigue and altered visual and perceptual abilities. Although techniques exist to limit this conflict for screen-based stimuli, the use of helmet visuals (or immersive headsets) adds technological complexity. Indeed, since accommodation on the screen of the helmet visual is impossible (i.e., distance too small) for the human visual system, lenses are used to virtually shift the image (referred to as a collimated image) so that accommodation can occur much further away. However, this material configuration also modifies the vergence, thus causing a conflict between accommodation and additional vergence that persists regardless of the attenuation technique used. In this study, the investigator proposed to modify the image display to take into account the technical features of the helmet to correct this techno-dependent conflict. This study is aimed at determining whether the setting recommended by the algorithm developed by the investigator limits visual fatigue better than the conventional setting recommended by manufacturers or a subjective setting controlled by the user.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 30
• Est. completion date: December 16, 2024
• Est. primary completion date: December 16, 2024
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age over 18
• Non-presbyopic
• Stereoscopic acuity = 60 min of arc

Exclusion Criteria:

• Accommodative insufficiency (APP = 13-"age"/4, in diopters)
• Accommodative inertia (+ and - block in binocular)
• Compensation by orthokeratology
• Present or past binocular pathology: strabismus or amblyopia

Related Conditions & MeSH terms

• Asthenopia
• Visual Fatigue

Intervention

Other:
• Oculomotor tests
There will be four visits. Each visit is associated with a different exposure in terms of level of oculomotor conflict. At each visit, several oculomotor tests will be performed, followed by a comfort questionnaire. The oculomotor tests are subjective tests during which the participant will be asked to fix his/her eyes on one or more targets that can move in space and to indicate the way he/she perceives this/these target(s). Depending on the test, lenses may be inserted between the participant and the target to modify his/her perception. The comfort questionnaire consists to rate on a scale of 1 (not at all) to 5 (very much) the presence of visual symptoms, such as burning, watering or dryness. The participant will then have to perform four different perceptual tasks. His/her level of accommodation (i.e. focus) will be monitored throughout the tasks. Each exposure is followed again by eye tests and a comfort questionnaire.

Locations

Country	Name	City	State
France	Institut de Recherche Biomédicale des Armées	Brétigny-sur-Orge

Sponsors (1)

Lead Sponsor	Collaborator
Direction Centrale du Service de Santé des Armées

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Evolution of oculomotor response to a stimulation generating jumps in vergence demand	Oculomotor response (accommodation and vergence) will be measured continuously via a single objective system (PowerRef 3) at each visit.	Until the end of the study (20 months)