Comparison of Different Refraction Measurements in Adults

Study Overview
=================
Brief Summary
-----------------
The combatant is likely to carry out missions any time, any place, day or night. The very strong degradation of natural vision performance in these conditions justifies the use of visual replacement means, based on optronic sensors whose sensitivity is more adapted to these luminous environments than that of the human eye. The duration and repetition of missions carried out with night vision sensors lead to visual complaints from users. The literature on night vision binoculars adjustment states that a binocular adjustment of the equipment provides more convex settings. The latter would then limit the strain on the accommodative component, which is one of the possible sources of operator visual fatigue. In order to allow a more appropriate adjustment, it is proposed to rely on a measurement of the refraction (optical defect of the eye) of each operator. Like binocular adjustments, binocular refractive methods would limit accommodative stimulation and thus visual fatigue. However, these methods are little used in favour of conventional methods. It is therefore necessary to evaluate the interest of binocular refraction for the adjustment of night vision binoculars. The purpose of this study is to compare refraction measurements by procedure in adult subjects free of ophthalmological disorders.

Official Title
-----------------
Comparison of Different Refraction Measurements in Adults

Conditions
-----------------
Vision Loss Night

Intervention / Treatment
-----------------
* Behavioral: Questionnaire
* Other: Eye examination


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age over 18 ; Non-presbyopic subject; Stereoscopic acuity ≤ 60 arc seconds. Exclusion Criteria: Accommodative insufficiency; Accommodative inertia; Compensation by orthokeratology (i.e. night lenses); Present or past binocular pathology (strabismus or amblyopia); Pregnant or nursing woman; Incomprehension of French (written and spoken).

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: Questionnaire|Questionnaire about habits in terms of near vision activities|
|Other: Eye examination|The eye examination involves the following measurements: Distant vision phoria with Thorington method Close vision with Thorington method Objective eye-to-eye refraction with self-refractometer Binocular objective refraction with autorefractometer Monocular/biocular/binocular refraction with Nidek TS610 SiView automatic refraction Humphriss binocular refraction MOU Binocular refraction|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum convex equivalent sphere values | Maximum convex equivalent sphere values obtained by the different refraction procedures under study. | At visit 1 (day 1) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| High contrast monocular acuity values | High contrast monocular acuity values obtained by the different refraction procedures. | At visit 1 (day 1) | 
| Low contrast monocular acuity values | Low contrast monocular acuity values obtained by the different refraction procedures. | At visit 1 (day 1) | 
| High contrast binocular acuity values | High contrast binocular acuity values obtained by the different refraction procedures. | At visit 1 (day 1) | 
| Low contrast binocular acuity values | Low contrast binocular acuity values obtained by the different refraction procedures. | At visit 1 (day 1) | 
| Difference between binocular perceptual assessment scores before and after subjective adjustment | Difference between binocular perceptual assessment scores obtained by the different refractive procedures before and after subjective adjustment. Binocular perceptual assessment score will be obtained using visual analogue faces. The score will range from excellent comfort to unbearable. | Difference between visit 1 (day 1) and visit 2 |