Значение идиомы open one’s eyes

[open one’s eyes] or [open up one’s eyes] {v. phr.} To make aperson see or understand the truth; make a person realize; tell aperson what is really happening or what really exists.

Mary didn’tbelieve that her cousin could be mean until the cousin opened Mary’seyes by scratching and biting her.

John’s eyes were opened up tothe world of nature when he visited his grandfather’s farm.

Compare:EYES OPEN, WISE UP. – [eye opener] {n.} Something that makes youunderstand the truth.

Pam’s first visit to school was a realeye-opener.