If you are dry-eyed, you are not crying. There are no tears. Writers use it when they want you to notice that someone stayed calm, or hard, or simply could not cry, even when the moment was sad and other people were in tears. It is a little literary; in plain talk you would just say 'she didn't cry.' You can be dry-eyed because you are strong, because you are numb, or because you will not show feeling. The word does not tell you which. Though actually, this is not the same as 'dry eyes' — that is when eyes feel sore and sandy because they lack moisture, a body problem, not a feeling.

沒有流淚、沒哭（不是「乾眼症」）