How Good Is Spiders Vision?
WouterSpiders have two main eyes. These are positioned on either side of the head. The secondary eyes are located near the main two to help them detect the movement of objects. They help the spider determine distance to their prey.
There are many spiders with decent vision. Some species, such as jumping spiders, can see far away objects. Others, such as the net-casting spider, need to have good vision to catch their prey.
The primary eyes of spiders have four distinct photoreceptor layers. The inner layers absorb a wide variety of light, including ultraviolet and green light. However, the retinas of these spiders can only pick up a limited amount of dim light. In order to better detect the light, the eyes have special filters.
The primary eyes of jumping spiders have a pair of UV filters and a ruby red filter pigment. The ruby red filter allows pigment cells to pick up more colors. The corresponding secondary eyes, which are also located near the primary eye, are responsible for the detection of less important signals.
Spiders have many other eyes as well, including a motion detector in the side of the head. Researchers believe that these eyes are used to detect the looming presence of prey. These detectors may be the most important feature of a spider’s visual apparatus.
The jumping spider’s superpower is its ability to see green. The pigments in its eyes help it discern the color of a nearby object. In addition, its secondary eyes can detect movement from afar.
