I was reading that they use their hair that they cant see

No. Most spiders are nearly blind,but the salticids (jump spiders) do have rather keen eyesight.

It is a theory that they can also see into the ultraviolet spectrum.

It has been shown that some flying insects are able to see in the IR spectrum, hence their ability to fly in darkness.

It would be more likely that the IR illumination on your camera is attracting these flying insects, and the spiders are webbing there for the food.

In spite of having as many as 8 eyes, most spiders have very poor eyesight.

A few spiders, often found in caves, have no eyes, and quite blind.

A few other species do have very good eyesight, such as wolf spiders and jumping spiders.

It is possible that the jumping spiders have eyesight superior to humans.

Most spiders, however, do have a very keen sense of feel. Those that make webs to hunt prey,'feel' vibrations in their web, and can find a bug that is caught in the web.

Hunting spiders also have sensitive hairs on their legs, and can feel miniscule air currents from flying insects.

The huntsman spider for example, has rather poor eyesight, but can hunt in total darkness.

Spiders also use small appendages called pedipalps that they use for taste and smell, and chemoreceptors also help in finding prey or even mates from pheromones.

Well i once read humans cant see so they use there hair to help them see!!

Some can see in the dark. Many pictures of wolf spiders show their eyes shining.