Lenses in Last Epoch are specialized items that players can equip in telescopes within the Circle of Fortune faction to significantly improve the chances of obtaining specific types of loot from Prophecies. Introduced near the end of the campaign (Chapter 9), the Circle of Fortune and its telescopes help reduce randomness in item farming Last Epoch Gold, making grinding more efficient and targeted.

To use Lenses, you must first reach the Circle of Fortune faction and interact with one of the four telescopes in the Observatory. Each telescope corresponds to a different loot category. Initially, you can slot only one Lens, but by increasing your Circle of Fortune rank (up to Rank 9), you unlock up to three Lens slots. Equipping multiple Lenses of the same type stacks their effects, further increasing your chances for specific rewards.

Lenses are purchased from Circle of Fortune vendors using Favor, the faction currency earned by completing Prophecies and related activities. There are two main types of Lenses:
1. Regional Lenses: These are tied to specific telescopes and loot categories, such as Armor, Weapons, Idols, and Jewelry. They become available from Circle of Fortune Rank 2 onward.
2. Greater Lenses: More powerful and versatile, these can be equipped on any telescope. They become available between Ranks 3 and 8 and include lenses that increase chances for Set, Exalted, or Unique items, or modify Prophecy conditions like blocking certain event types or doubling rewards.

According to community and tier lists, the most effective lenses are those that increase Prophecy uses or rewards, such as:
- 2x Uses Lens: Halves the number of Prophecies needed for a given amount of loot.
- 2x Quantity Lens: Doubles the rewards from completing Prophecies.
- Refracting Lens of Wealth: Considered the best overall for maximizing loot value.
- Obscuring Lens of Storytelling: Useful for avoiding campaign backtracking.
- Enhancing Lens of the Unmatched: Boosts chances for Unique and Legendary Potential Prophecies.

Some lenses are less effective or even counterproductive:
- Enhancing Lens of the Collector: Boosts Set items, which are generally weak and reduce chances for better items like Exalted or Unique Last Epoch Gold for sale.
- Eos Lenses: Due to a diluted loot pool, focusing on weapon types here is less efficient than using Greater Lenses and rerolling for better Prophecies.