The United Nations designated 2015 as the International Year of Light to mark several scientific anniversaries converging in that year — among them the 1,000th anniversary of Ibn al-Haytham's Book of Optics and the 150th anniversary of Maxwell's equations describing electromagnetic radiation. San Marino, as a non-EU microstate that retains its own euro-denominated coinage rights through bilateral agreement with Italy, routinely issues commemorative silver pieces for UN-designated years, keeping mintages low enough to sustain collector demand without flooding the market.
The United Nations designated 2015 as the International Year of Light to mark several scientific anniversaries converging in that year — among them the 1,000th anniversary of Ibn al-Haytham's Book of Optics and the 150th anniversary of Maxwell's equations describing electromagnetic radiation. San Marino, as a non-EU microstate that retains its own euro-denominated coinage rights through bilateral agreement with Italy, routinely issues commemorative silver pieces for UN-designated years, keeping mintages low enough to sustain collector demand without flooding the market.