addition of 0 5 w v tramadol this formulation was administered to the left eye of a healthy 47 year old subject sensation in the left eye was noticeably reduced within 3 minutes of instillation of the tramadol formulation and this numbing effect lasted for at least 110 minutes sensation in the right eye remained normal no side effects were noted in a fourth example administration of the tramadol containing eye drop formulation of the third example to a patient suffering from u201c dry eye u201d reduced the resultant discomfort as expected however this reduction of discomfort apparently led to a reduction in blinking dryness remained and the physical signs did not improve when a conventional u201c artificial tears u201d composition was applied instead this composition containing a lubricating formulation comprising sodium hyaluronate hypromellose and or carbomer gel the eye was better lubricated and physical signs improved however the discomfort remained which for many patients would lead to actions such as rubbing the affected eye counteracting much of the improvement when 0 5 w v tramadol was added to the lubricating u201c artificial tears u201d composition however and this combination was administered to the eye pain and dryness were reduced simultaneously and all symptoms and signs improved significantly more rapidly in a fifth example a conventional u201c artificial tears u201d formulation was made up as a standard containing an aqueous ophthalmic lubricating formulation comprising sodium hyaluronate hypromellose and carbomer gel a new u201c artificial tears u201d formulation embodying the present invention was also made up having substantially the same composition as the conventional formulation above with the addition of 0 5 mg tramadol per 100 ml of u201c artificial tears u201d i e 0 5 w v tramadol the conventional artificial tears formulation.