I think it depends who does the test. If it is a biometrist or a nurse hey are probably not allowed o discuss the results with you . They are supposed to leave it to the doctoras . I suppose that it is BECAUSE it is the hospital and the fact hat you are there might indicate hat there is some cause for concern . The person doing he screening may not be qualified to interpre the information correctly. The opticians are in a different position. If they suspect anything serious they are either better qualified han the people screening in the hospital or they are only giving you he basic information you would receive in your results letter.
At least that is what I imagine. The optician can refer you to the hospital but the hospital need the experts to make a diagnosis.