Ahzidal's Helm of Vision is a unique Ancient Nord Helmet and part of Ahzidal's Armor set found in The Elder Scrolls V: Dragonborn.
Acquisition
It can be obtained in Kolbjorn Barrow on a pedestal behind a puzzle gate during the fourth investment stage of the quest "Unearthed."
Enchantment
Your Conjuration and Rune spells cost 25% more, but can be cast at greater range.
The enchantment on this helmet is quite self-explanatory; choosing to equip this piece of headgear would be useful for players who frequently cast runes or conjure allies from Oblivion. Note that this enchantment does not affect bound weaponry.
Smithing
It can be upgraded with a steel ingot at a workbench and also benefits from the Advanced Armors perk, which doubles the improvement.