Crown of Eyes is a unique helmet in Path of Exile, classified as a Hubris Circlet, notable for its powerful hybrid scaling mechanic that benefits both spell and attack damage. It requires level 69 and 154 Intelligence to equip, making it a late-game item primarily suited for caster or hybrid builds that mix spells and attacks PoE 1 Currency.

Key Stats and Effects
1. Energy Shield: 192–248 base, with 120–150% increased Energy Shield  
2. Accuracy Rating: +300 to +350, which helps smooth out attack scaling, especially for builds combining spells and attacks  
3. Leech: 0.4–0.8% of attack damage leeched as life and 0.2–0.4% leeched as mana, providing sustain for both resources  
4. Unique Modifier: "Increases and Reductions to Spell Damage also apply to Attacks at 150% of their value" — this is the defining feature, allowing spell damage modifiers to boost attack damage significantly, opening up powerful hybrid build possibilities.

How the Unique Modifier Works
This modifier means that any increased or reduced spell damage on your gear, passives, or auras will also affect your attack damage, but at 150% effectiveness. For example, if you have +100% increased spell damage, your attacks will gain +150% increased damage as well. This enables builds that invest heavily in spell damage nodes or gear to also benefit their attacks, creating strong synergy for hybrid playstyles.

However, the modifier only applies to "increased" and "reduced" spell damage stats, not other spell-related stats like added elemental damage to spells or critical strike chance for spells.

Trade-offs
1. The helmet reduces Fire Resistance by 30%, which is a significant drawback and requires players to compensate with other gear or flasks to maintain survivability.  
2. The high Intelligence requirement limits its use to certain classes or builds that can meet the stat demand.

Usage and Build Synergies
Crown of Eyes is highly valued in builds that combine spells and attacks, such as:
1. Wand users who cast spells but rely on attacks for damage  
2. Hybrid melee casters like Blade Vortex + Cyclone setups  
3. Cast-on-Crit builds that benefit from both spell and attack scaling  
Its large boost to Energy Shield and accuracy also helps enhance survivability and hit chance, making it a versatile helmet for many caster-attack hybrids buy PoE Currency.

Summary
Crown of Eyes remains a unique and powerful helmet that enables creative hybrid builds by bridging the gap between spell and attack damage scaling, at the cost of a hefty fire resistance penalty. It is a cornerstone item for players looking to maximize damage output through unconventional scaling methods in Path of Exile.