You seem to have ptosis(drooping eye lid) in the right eye. The causes could be neurogenic, myogenic, aponeurotic or mechanical. Since, the ophthalmologist could not see anything abnormal they are looking for a neurogenic cause like an aneurysm or something. It 's not that something will show up. They just want to ensure that everything is normal. Otherwise your symtoms were suggestive of raised eye pressure i.e. glaucoma but that must have been ruled out by the ophthalmologist. Your treating doctors would be able to give a better answer as they are the ones who have examined you. Thanks and best wishes.
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