The search textbox has an autosuggest feature. When you enter three or more characters, a list of up to 10 suggestions will popup under the textbox. Use the arrow keys to move through the suggestions. To select a suggestion, hit the enter key. Using the escape key closes the listbox and puts you back at the textbox. The radio buttons allow you to toggle between having all search items start with or contain the text you entered in the search box.
A thin layer of tissue that is part of the middle layer of the wall of the eye, between the sclera (white outer layer of the eye) and the retina (the inner layer of nerve tissue at the back of the eye). The choriod is filled with blood vessels that bring oxygen and nutrients to the eye.