# Influence of short-term hypoxia exposure on dynamic visual acuity

## TL;DR

This study examines how short-term exposure to high-altitude hypoxia affects dynamic visual acuity, which is important for pilots' ability to see and make decisions.

## Contribution

The study reveals how hypoxia and angular velocity jointly influence dynamic visual acuity in a controlled experimental setting.

## Key findings

- DVA generally decreases with increasing angular velocity at constant altitude.
- DVA increases with altitude up to a point, then decreases as altitude continues to rise.
- DVA recovers and improves as altitude decreases after hypoxia exposure.

## Abstract

To quantify the changes in dynamic visual acuity (DVA) and explain the hidden reasons after acute exposure to hypobaric hypoxia status.

The study group comprised 18 healthy male and 15 healthy female participants aged 20–24 years old. DVA was measured with the self-developed software of Meidixin (Tianjin) Co., Ltd. Measurements were taken at eight altitudes. Data analysis was performed using the Kolmogorov–Smirnov test, paired sample T-test, and two-way repeated measures analysis of variance (ANOVA) for repeated measurements.

At constant altitude, DVA showed an overall decreasing trend with increasing angular velocity and a fluctuating decrease at the vast majority of altitudes. At constant angular velocities, DVA gradually increased with altitude, with the most pronounced increase in DVA at altitude 5, and thereafter a gradual decrease in DVA as altitude increased. Finally, as altitude decreased, DVA increased again and reached a higher level at the end of the experiment, which was superior to the DVA in the initial state.

Under a hypobaric hypoxic environment at high altitude, DVA was affected by the angular velocity and the degree of hypoxia, manifesting as an increase or decrease in DVA, which affects the pilot's observation of the display and control interfaces during the driving process, acquisition of information, and decision-making ability, which in turn may potentially jeopardize the safety of the flight.