Vessels of Sight

What am I looking at?

This is an image of the intricate network of blood vessels in the retina of a mouse. The image is depth-coded for color, which means that cooler colors like blue and green (1) represent elements closer to the viewer and warmer colors like yellow and red (2) are farther away.

Biology in the background

The retina is a layered structure, consisting of photoreceptor cells, a layer of interneurons, and retinal ganglion cells at the back of the eye. Photoreceptors detect light and allow us to see. They are specialized cells and, like other cells, require nutritional support to function properly. These nutrients are provided by the blood vessels that spread throughout the retina. The blood vessels in the retina are very small and can break relatively easily. That is one of the reasons it is important to protect your eyes as much as possible.

The blood vessels in the retina vary in size a great deal. The larger veins and arteries in a mouse retina can be up to 50 micrometers in diameter, or slightly smaller than the width of a human hair. The smallest capillaries can be only 3 micrometers in diameter, or roughly 25 times smaller than the width of a human hair.

Technique  

This image was created using confocal microscopy.