This is the 5177th most frequent Korean word.
눈부신
Dazzling; brilliant; radiant.
The word '눈부신' is used here to describe the extraordinary beauty of 'her smile', using it as an adjective representing brilliance or radiance.
그녀의 웃음은 눈부신 아름다움을 보여줬다.
Her smile showed dazzling beauty.
In this sentence, '눈부신' is applied to '햇살' (sunlight) to denote brightness and the intense radiance of the sun.
눈부신 햇살 아래에서 산책을 즐겼다.
We enjoyed a walk under the dazzling sunlight.
Here, '눈부신' modifies '업적' (achievements), illustrating metaphorically the outstanding and remarkable nature of his accomplishments.