Spidereyes

Spidereyes was a spell to see through the eyes of a spider.

Effects
Spidereyes did two things. First, it created a link between a touched spider and the caster. This link allowed the caster to see through the eyes of the aforementioned spider. Second, the spell "translated" the spider's vision, so that the caster could understand it. This was necessary, because a spider usually had eight eyes, out of which two were compound, six simple. This difference in spider and humanoid anatomy made "translation" necessary.

The link between caster and spider could be broken by sending one party to a different plane. It could also be blocked by a magical barrier like a minor globe of invulnerability.

What this spell did not do was give the caster any capacity above seeing through the spider's eyes. The caster did not have any control over the bonded spider nor any ability to read its mind.

Components
The spell required somatic and verbal and also material components, namely a strand of web and a spider on which to cast the spell. Clerics did not need the web.

History
The spell was developed by the drow. It had two uses. First, it was used to turn a harmless spider into a spy. This was frustrating, because, as mentioned above, the spell did not confer any control over the spider, therefore making it hard for the caster to make the spider move in or look into a certain direction. Second, the spell was used to combat hostile giant spiders. By understanding the vision of the enemy, the caster got an idea of its blind spots.

The ability to use it was among the things an arachne learned. They used it to see through their hairy spider familiars.