Monocular O (Capital: Ꙩ, minuscule: ꙩ) is one of the rare glyph variants of Cyrillic letter O. This glyph variant was used in certain manuscripts in the root wordꙩко (eye),[1] and also in some other functions, for example, in the word- and syllable-initial position. It is used in some late birchbark letters of the 14th and 15th centuries, where it is usually differentiated from a regular о, used after consonants, also by width, being a broad On (ѻ) with a dot inside.