The present invention relates to a method for treating a dry eye syndrome using an alpha 2 adrenergic agonist, pharmaceutically acceptable salt thereof or a mixture thereof. In particular, the alpha 2 adrenergic agonist of the invention has a higher alpha 2A agonist activity compared to alpha 2B agonist activity. This invention also relates to an ophthalmic composition comprising a therapeutically effective amount of an alpha 2 adrenergic agonist, a pharmaceutically acceptable salt thereof or a combination thereof as an active ingredient for treating a dry eye syndrome.