Gemini Defense makes a handgun sighting system that is supposed to allow the shooter to focus on the threat, not the sights, in a high-stress self-defense situation.  The sights are called Zone Reflex, or Z-Flex, combat sights.

The rear sights offer either a large, oblong, enclosed circle or a very wide, tall notch depending on the model purchased.  All of the sights use parenthesis-like outlines to bracket the target.  The purpose is for the shooter to concentrate on the threat while obtaining a non-precise, but fast visual reference that the gun is on target.

The two enclosed rear sights also have a standard notch at the base to allow for more precise shooting at targets farther away.

The sights use a photo-luminescent paint that glows after being exposed to light.  Roughly one minute of “charging” from a high intensity flashlight should provide up to six hours of useful glowing.

Pricing runs from $89.95 to $119.95.