Eye of Akasha

Eyes of Akasha were small, red, spherical objects the size of cricket balls. They would give off light and tertiary radiation.

In one of his earlier incarnations, the Doctor kept a broken Eye of Akasha in his house on Allen Road. At some time after the 1980s, a squadron of Judoon came to get the Eye. He swapped it with a cricket ball and let the Judoon leave with it. (IDW: The Forgotten)