Shadows in the Void
The first Demon’s Eye was so coined ages ago when they were seen from afar. Something about certain nebulae will cause a Stygian Gate inside them to glow a orange-red light making the nebulae look like some sort of demonic eye, hence the name.
Any ship emerging from a gate into a demon’s eye is likely to find extreme turbulence due to the interaction between the gate and the nebula that causes it to glow. Whenever a ship enters the nebula the gate will give off an extra bright light. From afar this can cause the eye to look like it is winking. Once the ship is through the turbulence tends to subside allowing the ship to explore hidden parts of the nebula.
Demon’s Eyes are popular smuggling hideouts due to two factors, firstly the nebulae provide a means to hide from the sensors of other ships and secondly it is easy to see when another ship enters the nebula due to the flash of light.