a euphemism

'the period after 843 was one of consolidation followed by slow but steady expansion in the political power of the Byzantine Empire. . . . The Bulgarian threat was neutralized by 1018 (a euphemism for Emperor Basil II's decision to blind the 14,000 Bulgarian soldiers captured in battle in 1014, leaving every hundredth man with one eye to guide his companions back to Tsar Samuel, who died of shock at the sight).'

'John Lowden, Early Christian & Byzantine Art, 1997.