Truly striking are the four forward facing eyes. Another four smaller eyes are located at the sides and on top of the head. Together, these 8 eyes provide a 360 degree view. The 8 eyes also allow the spiders to see a massive amount of detail, despite their tiny size. Additionally, the spiders’ retinas can swivel on their own, allowing the spider to look around without moving its head.
By the way: Spider eyes are different from insect eyes; they are not compound but simple. There is one lens for each eye, made of a thin layer of the cuticle. Below that is the retina, the actual light-detecting cells.
For more information about spider eyes I recommend the article ‘Spider Vision Made Clear‘.