1. Vision is the dominant sense for many animals, and there is an enormous diversity in
visual capabilities. Understanding the visual abilities of a given species can therefore be
key for investigating its behaviour and evolution. However, many techniques for
quantifying visual capability are expensive, require specialized ...
1. Vision is the dominant sense for many animals, and there is an enormous diversity in
visual capabilities. Understanding the visual abilities of a given species can therefore be
key for investigating its behaviour and evolution. However, many techniques for
quantifying visual capability are expensive, require specialized equipment, or are
terminal for the animal.
2. Here, we discuss how to measure the optomotor (or optokinetic) response, an innate
response that can be elicited without any training in a wide range of taxa, and which is
quantifiable, accessible, and non-invasive, and provide guidance for carrying out
optomotor experiments.
3. We provide instructions for building a customizable, programmable optomotor
apparatus using 3D-printed and low-cost materials, discuss experimental design
considerations for optomotor assays, include a guide that calculates the dimensions of
stimuli of varying spatial frequency, and provide a table summarizing experimental
parameters in prior optomotor experiments across a range of species.
4. Ultimately, making this simple technique more accessible will allow more researchers to
incorporate measures of visual capability into their work. Additionally, the low cost and
ease of construction of our apparatus will allow educators in a variety of settings to
include optomotor assays in classroom activities or demonstrations. Although here we
focus on using optomotor to measure visual acuity—the ability to perceive detail—the
apparatus and stimuli described here can be adapted to measure visual capabilities
including spectral, contrast, and polarization sensitivity, as well as motion detection,
among others.
