The invention is a tool that may be attached to a computer display screen or built-in with a computer. The tool is mounted to a computer and provides a user with the ability to align the computer display screen with their eye so that the user's line of sight is perpendicular to the display screen, which is the optimal viewing angle for viewing a display screen. In a first embodiment of the invention, the tool includes an interface portion, which is where the tool is attached to the frame of the computer, either temporarily or permanently, and an alignment portion. The first embodiment of the alignment tool may be detached from one computer and used with another. The alignment portion includes a pair of alignment indexes, which, when lined up with the user's eye, ensures that the user is viewing the computer display screen at the optimal angle. In a second embodiment of the alignment tool, the tool is installed as original equipment on the computer. The second embodiment of the alignment tool includes a pair of alignment indexes and is movable between an open position and a closed position by a spring.