Most spiders have eight eyes, typically arranged in pairs, but the exact number can vary by species. Some spiders have six, four, two, or even no eyes at all, especially those adapted to dark environments like caves
. The eight eyes usually consist of a pair of principal eyes (anterior median eyes) and several pairs of secondary eyes positioned around the head. These eyes serve different functions: the central eyes detect size, shape, and color, while the side eyes are more sensitive to motion
. Despite having many eyes, most spiders have relatively poor vision and rely heavily on other senses such as vibration and touch to navigate and hunt. However, some species like jumping spiders, wolf spiders, and net-casting spiders have well-developed eyesight and use their eyes actively for hunting and recognizing mates or rivals
. In summary:
- Most spiders have 8 eyes arranged in pairs.
- Some species have fewer eyes (6, 4, 2) or none.
- Eye arrangement and number vary by species and habitat.
- Vision quality varies; some spiders have sharp vision, others rely on other senses
