Eyepiece

An eyepiece was a device containing a lense that could be attached to a Kanohi, allowing the wearer of the mask to zoom in or out. On Metru Nui, eyepieces were crafted by maskmakers. They were popular among Ko-Matoran seers. It is known that before he became a Toa Metru, Vakama made Nuju one for his Matatu.

Masks with eyepieces

 * Akaku (Great version)
 * Matatu (Great version)
 * Akaku Nuva

Trivia

 * When Matoro used the eyepiece on his Akaku, it triggered many speculation among fans that Matoran could use mask powers.