18th-century Changes
The printed Russian alphabet began to assume its modern shape when Peter I introduced his civil script (гражданскій шрифтъ, graždanskij šrift (spelled "гражданский шрифт" in modern Russian), ) in 1708. The reform was not specifically orthographic in nature. However, with the effective elimination of several letters (Ѯ, Ѱ, Ѡ, Ѧ) as well as all diacritics and accents (with the exception of й) from secular usage, there appeared for the first time a visual distinction between Russian and Church Slavonic writing. With the strength of the historic tradition diminishing, Russian spelling in the 18th century became rather inconsistent, both in practice and in theory, as Mikhail Lomonosov advocated a morphological orthography, Vasily Trediakovsky a phonetical one.
Read more about this topic: Reforms Of Russian Orthography