Cow Eye dissection

This year we are doing Human Anatomy for science and one of the highlights has been the chance to do dissections. We dissected a sheep's brain a few months ago and grossed out our house cleaner, but failed to get any photos. We moved on from the brain & nervous system to the eye and snapped a single picture. Tom delicate stomach kept him in the next room, and Tim and I wrote off any future career in medicine. Sam sat next to me the whole time, but lacked the fine motor coordination to actually do any cutting, which was harder than it looked. The scalpel that came with the kit was not really up to the task; I really should have used one of my kitchen knives, but just didn't want to. So I sawed away with the scalpel and tried not to maul the eye too badly in the process.

Here is the eye after it has been cut in half. The bits on the left are from the thick cushion of fat swathing the eye. After it was opened the vitreous humor leaked out and we were able to examine the lens, which is the yellowish disc in the center. Sam and I both held it up to our eyes and against the newspaper to see how it magnified things. The iridescent part on the lower half is called the tapetum and is only in animal eyeballs. That surface reflects light back out through the eyeball at night and is the reason for the "glowing eyes" we see whenever we shine a flashlight in our dogs' faces at night.