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INTRODUCTION: We evaluated the reproducibility of two portable, self-administered autorefractors (Netra and SVOne Pro) to assess the time course of visual changes on the ISS. METHODS: We measured cycloplegic refractive error at 5 visits at least a week apart in 13 subjects (6 women, 7 men, 30 ± 9 yr) using both devices seated and also prone with lower body positive pressure (LBPP) applied. Axial length was measured with an optical biometer. Subjects completed a questionnaire on device preferences. RESULTS: The SVOne seated intrasession reproducibility coefficient (RPC) was 0.37 diopters (D), while the Netra's was 0.41 D. Intersession seated results were: RPC = 0.67 D for the SVOne and RPC = 0.54 D for the Netra. The average seated to prone LBPP differences were significantly different from zero for both the SVOne and Netra. The SVOne was preferred in four out of five categories on the questionnaire and took half the time to complete a measurement set compared to the Netra. DISCUSSION: Users preferred the SVOne and it took less time. An SVOne refraction change of 0.67 D from baseline would happen by chance less than 5% of the time. If multiple separate measurements were taken, the detection limit could be reduced (e.g., three repeated measurements could reduce it to 0.38 D). Since astronauts with visual changes show spherical equivalent changes of 0.5 to 1.0 D, in-flight autorefractors could help determine the time course of refractive changes in space from which changes in axial length could be inferred. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Virtual reality (VR) can provide exposure to nature for those living in isolated confined environments. We evaluated VR-presented natural settings for reducing stress and improving mood. METHODS: There were 18 participants (9 men, 9 women), ages 32 ± 12 yr, who viewed three 15-min 360° scenes (an indoor control, rural Ireland, and remote beaches). Subjects were mentally stressed with arithmetic before scenes. Electrodermal activity (EDA) and heart rate variability measured psycho-physiological arousal. The Positive and Negative Affect Schedule and the 15-questlon Modified Reality Judgment and Presence Questionnaire (MRJPQ) measured mood and scene quality. RESULTS: Reductions in EDA from baseline were greater at the end of the natural scenes compared to the control scene (-0.59, -0.52, and 0.32 jxS, respectively). The natural scenes reduced negative affect from baseline (Δ = 1.2 and Δ = 1.1 points), but the control scene did not (Δ = 0.4 points). MRJPQ scores for the control scene were lower than both natural scenes (4.9,6.7, and 6.5 points, respectively). Within the two natural scenes, the preferred scene reduced negative affect (Δ = 2.4 points) more than the second choice scene (Δ = 1.8 points) and scored higher on the MRJPQ (6.8 vs. 6.4 points). DISCUSSION: Natural scene VR provided relaxation both objectively and subjectively, and scene preference had a significant effect on mood and perception of scene quality. VR may enable relaxation for people living in isolated confined environments, particularly when matched to personal preferences. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Living in an isolated, confined environment (ICE) can induce conflict, stress, and depression. Computer-based behavioral health countermeasures are appealing for training and treatment in ICEs because they provide confidentiality and do not require communication with the outside environment. We evaluated the Virtual Space Station (VSS), a suite of interactive computer-delivered psychological training and treatment programs, at the Hawaii Space Exploration Analog and Simulation (HI-SEAS) III expedition. METHODS: Six subjects (3 male, 3 female) spent 8 mo in group-isolation and used the Conflict, Stress, and Depression modules in the VSS. Survey evaluations, data collected within the program, and postdeployment interviews were collected. RESULTS: This crew dealt with behavioral health issues common to ICEs. The VSS proved to be a valuable resource and was used both as intended, and in unanticipated ways, to help maintain behavioral health. The Conflict and Stress Modules were rated as highly acceptable (1.8 on a 7-point Likert scale). The crew identified a total of 13 stressors and worked on 9 problems through the VSS. Opinions about the modules were highly individualized. Crewmembers identified exercises in the VSS that were applicable and not applicable to their needs. Additional content to improve the program was identified. DISCUSSION: Autonomous, confidential training and treatment for behavioral health issues will need to be a critical component of long duration spaceflight travel. This work provides an evaluation of such a tool in a relevant ICE. [ABSTRACT FROM AUTHOR]