Pupil Shape in the Animal Kingdom

Methods

In this project, we utilized ISETCam and ISETBio to simulate the imaging process that occurs within an animal's eye.

The flow chart illustrates the simulation process, with the examples below each step.

Scene

We created two types of scenes for our simulations: sceneCreate.m to generate gridlines and sceneFromFile.m to read an image. The gridlines illustrate the effects along different axes, while the image provides a visualization of what the animal might be seeing.

Aperture

The aperture represents the pupil shape and is modeled as a 201x201 matrix. In this matrix, ones indicate the regions where light can pass through (white), while zeros denote the areas where light is blocked (black). For the single-slit elliptical aperture, we can adjust both the size and the orientation of the ellipse (vertical or horizontal). For the multiple-slit aperture, we can modify the slit length, slit width, and the number of slits. For the w-shaped aperture, we intake the w-shape black and white image to generate the aperture matrix, and are able to change the size of it.

Point spread function and Optical image

The point spread function was simulated for each aperture to analyze the impact of aperture shapes on light passing through the aperture. This was achieved by creating a diffraction-limited wavefront structure using wvfCreate.m and computing the point spread function with wvf.Compute.m with the aperture matrix as input. The optical image was generated using oiCompute.m taking in the scene and the aperture matrix as inputs. The simulation process assumes that the optical lens is diffraction-limited.

Cone Mosaic and Absorptions

To simulate how the eye’s sensor processes the scene, we modeled the human cone mosaic using cMosaic.m in ISETbio, and used cm.compute.m to simulate the cone excitations and absorptions. Due to time constraints, we only tried the human cone distribution, but it would be highly valuable to try incorporating known cone distributions from the literature for various animals in the future.

Appendix

You can write math equations as follows: $y=x+5$

You can include images as follows (you will need to upload the image first using the toolbox on the left bar, using the "Upload file" link).