Here's something I want to share with you:
The eyesight of wolves is not fully understood, thought it is probably similar to that of domesticated dogs. Compared with humans, wolves have three to four times the density of light-sensing rods in their retinas, which gives them keener night vision. Yet because they lack a fovea (the tiny pit on the retina) they cannot match a human's ability to focus on objects at a long distance.
The eerie, harmonic chorus howl so engrained in our collective unconscious is used both defensively and to rally the pack. Chorus howling also brings the wolves enjoyment, thought pack politics dictate that low-ranking wolves not to join in uninvited.