Ocular responses and visual performance after emergent acceleration stress.

Area of Science:

• Aerospace Medicine
• Ophthalmology
• Human Factors Research

Background:

• Acceleration stress is a critical factor in aviation and spaceflight.
• Understanding its impact on visual function is vital for safety and performance.

Purpose of the Study:

• To evaluate the effects of emergent acceleration stress on visual function.
• To assess ocular reactions and visual performance changes following high G-force exposure.

Main Methods:

• Sixteen subjects were exposed to +6 Gz using a human ejection seat trainer.
• Visual acuity, contrast sensitivity (CS), and ocular parameters (anterior chamber depth, pupillary dilation) were measured.
• Biomicroscopy and topographic mapping were used for ocular assessment.

Main Results:

• Significant temporary reduction in visual acuity and contrast sensitivity was observed immediately after acceleration.
• Increased anterior chamber depth and pupillary dilation persisted for over 15 and 30 minutes, respectively.
• Contrast sensitivity recovered to baseline at high spatial frequencies within 30 minutes.

Conclusions:

• Emergent acceleration force causes significant ocular responses and visual fluctuations.
• Prolonged anterior chamber depth and pupillary dilation occur, yet cornea and refraction remain stable.
• Visual fluctuation may involve neuroretinal function, warranting further investigation.