Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Vascular cast of choroidal vasculature taken with a scanning electron microscope. We thank Jolanta Sapieha for her expertise and technical help with the SEM image (Ecole Polytechnique, Montreal, Canada; supported by NSERC). Image is from the protocol by Connor et al. Cover design by Jamel Wooten.