Definition from Wiktionary, the free dictionary
During the Civil War that took place on the United States' soil, wounded soldiers battling with depression were given them as treatment. The theory was that the wearer would see things under a more positive light.
- Used other than as an idiom: glasses that are tinted in a pink or rose shade.
- (idiomatic) An optimistic perception of something; a positive opinion; seeing something in a positive way, often thinking of it as better than it actually is.
overly optimistic perception of something