It seems like Eye of Kertigen is over slot costed. No other darkvision or light source spells have a slot cost for their darkvision/light effects.
The 'primary' effect of passive search without point effect is basically the garden's vision enchantment and cantrip level power at best. Paladin sixth sense doesn't have a slot cost and that seems like it's basically what Eye of Kertigen does.

EYE doesn't buff a skill or stat and doesn't grant point effect. Sanctuary, fortunately, fills a Bard's anti-stealth needs but why does Eye of Kertigen cost 2 spell slots? It seems like it should be a zero slot spell (or reconceived as a new spell).