Border Collie Q&A
Dogs have what is known as a reflecting tapetum located behind the retina in the eyes which captures light and reflects it back at the retina giving the eyes a second chance to capture any available light especially in dim lighting conditions. This is what causes dog's eyes to glow. Husky-type dogs, especially those with blue eyes, may not have a reflecting tapetum so their eyes do not glow when illuminated. This is thought to be an accidental occurence resulting from selective breeding. In northern regions where these dogs were bred to work the ground is covered with snow most of the year which provides reflected ground light.