Lens (レンズ Renzu?) is an ancient mineral that serves as the primary source of energy in Tales of Destiny and Tales of Destiny 2. Business, politics, and religion revolve around the exploitation of this resource, leading to conflicts among the nations of the world throughout history. Lens is said to come from the fragments of an ancient meteor that crashed into the planet's surface prior to the split of the Er'ther and Aeth'er races. This meteor sent the planet into an ice age, of which the modern-day Phandaria region is a result.
Around 1,000 years prior to the events of Tales of Destiny, a large comet collided with the planet, scattering countless fragmented pieces of the comet known as Lens, which contain a special energy that can be drawn from the Lens and utilized in various forms, such as medicine and machinery. In addition, Lens has the potential of reacting to mental energy, making it possible to draw power from Lens through thought and concentration, a process known as crystallization (晶術 jiing shuu?, "crystal surgery"). Although Lens can be found virtually anywhere on the planet, it is mainly retrieved through the excavation of ruins and monsters of the Aeth'er Wars era.
Oberon Corporation has accumulated great wealth through these methods, forming a business out of excavating Lens and purchasing it from sellers through its regional branches. Oberon then uses the Lens to manufacture Lens-based products, such as weapons, nutrition drinks, and consumer electronics. It is possible to completely drain the energy from a Lens, rendering it a piece of inoperable glasswork. However, proper care and processing can enable Lens to function using nature as a source of energy, and these Lenses will continue to produce energy as long as they are not damaged. Examples of this processed Lens can be found in the Swordians and the Eye of Atamoni.
When the Lens-infused comet struck the planet, an ice age ensued, placing humankind on the verge of extinction. However, due to the discovery of Lens around the same time, the crisis was averted. Likewise, Lens played a major role during the Aeth'er Wars, ultimately influencing the outcome through its associated technology. Although Lens gradually became obsolete following the war, Oberon managed to renew its usefulness when it began around 20 years prior to the events of Tales of Destiny, making Lens-based products popular worldwide and expanding its company to different regions.
Nonetheless, Oberon's technology is inferior compared to the technology of the Aeth'er Wars era, which yielded the Swordians, Flying Dragons, and the devastating superweapon Belcrant. Due to the high value of Lens in Tales of Destiny, Lens-hunters such as the protagonist Rutee Katrea are common. In Tales of Destiny 2, however, the demand of Lens has significantly declined due to the drastic events of Tales of Destiny.