Flammer's scientific and medical endeavors were generally interdisciplinary. His first research focus was automatic perimetry for which he established normal values; he studied short term and long term fluctuations of the human
visual field and described influencing factors. Together with Hans Bebie, he developed the so-called Bebie curve, which plays a major role in the diagnosis of visual field loss due to glaucoma, he introduced the visual field indices. Flammer was one of the first researchers to demonstrate systemic side effects of locally administered
beta blockers (i.e. eye drops) in ophthalmology. Flammer and his collaborators found that
intraocular pressure variation is as important for the development of glaucoma, one of the main causes of blindness worldwide, as a constantly elevated intraocular pressure, long considered the main, if not the only, cause of glaucoma. In numerous research projects he demonstrated that glaucoma could be caused by a dysregulation of ocular blood flow, even at normal levels of intraocular pressure. Flammer discovered that vasospasms in the eye are a manifestation of a general vasospastic syndrome. Later, he noted that such spasms are only the tip of the iceberg and an indication of a much more generalized vascular dysregulation in the human body. This increases the risk of eye disease, in particular of normal tension glaucoma. Flammer noted that people with a primary vascular dysregulation have other symptoms and signs; this led to the establishment of the term
Flammer syndrome. Flammer also demonstrated the relationship between eye disease and heart disease. In numerous laboratory studies, he contributed to the understanding of the role of endothelin - which according to his studies regulates retinal venous pressure - and
nitric oxide in ocular perfusion. He also described the pathogenic role of ocular blood flow in
retinitis pigmentosa. ==Publishing and education==