Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Sample displays containing short contours (left) and long contours (right), showing several levels of complexity (DL). Complexity increases from top to bottom rows. Targets in this figure have augmented contrast compared to the experimental displays.
