have blinkers on

have blinkers/blinders (US) on (have or show inability to see or understand) — иметь шоры на глазах, иметь зашоренный взгляд

Example: He has blinkers on when it comes to politcs. — Когда дело доходит до политики, у него словно шоры на глазах.

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blinkers/blinders — a pair of flat pieces of leather fixed beside a horse's eyes to prevent sight of objects at his sides