"Glass no Hitomi" (硝子の瞳) is a single by Japanese visual kei rock band SID, released on January 18, 2017, by Ki/oon Records.

[1] It would be the opening of Kuroshitsuji: Book of the Atlantic, being the third theme song in the series made by the band, after "Monochrome no Kiss" and "Enamel".

The regular edition only has the tracks "Glass no Hitomi", its instrumental version and the B-side "Chiisana Tsubasa" (チイサナツバサ).

[5] The anime limited edition has a different cover, which shows the protagonists of Kuroshitsuji (Ciel Phantomhive and Sebastian Michaelis) instead of the band members, and comes with a bonus item.

[7] In an interview with OK Music website, Mao said that the drummer brought the key words so he could write about it, something that doesn't usually happen among the group.

[9] Yūya said that when reading the anime's story, he felt a "sad feeling" and then composed the song with the image of "fighting while crying".