Modelling the visual world of a velvet worm

Area of Science:

• * Comparative physiology
• * Animal vision
• * Biophotonics

Background:

• * Many animals possess simple, low-resolution eyes, making traditional optical analysis difficult.
• * Understanding the visual capacity of these eyes is crucial for ecological and evolutionary studies.

Purpose of the Study:

• * To develop and apply a novel modeling approach for assessing the functional capacity of primitive eyes.
• * To determine the visual acuity and spatial information processing capabilities of the velvet worm *Euperipatoides rowelli*.

Main Methods:

• * Developed a ray-tracing model incorporating 3D eye morphology reconstructions.
• * Calculated photoreceptor angular acceptance functions and visual acuity across the visual field.
• * Generated visual filters to simulate animal's visual perception.

Main Results:

• * The velvet worm eye exhibits asymmetry, with a deeper retina anteriorly.
• * Maximum visual acuity was calculated at approximately 0.11 cycles/degree in the forward direction.
• * Simulated visual filters accurately represent spatial information perceived by the velvet worm.

Conclusions:

• * The developed ray-tracing method effectively assesses visual function in simple eyes.
• * Velvet worm vision, though low-resolution, is sufficient for environmental orientation and positioning.
• * Findings align with previous behavioral studies on velvet worm visual acuity.