Early Detection of Functional Loss The HEP uses preferential testing of the magno-cellular system to enable early detection of functional loss and disease progression. Most commonly used visual field tests are broadband in nature and provide a general evaluation of visual function. But selective testing of the visual pathway enables the earlier detection of damage. HEP can selectively test the magno-cellular pathway for detection of early functional loss, whether such loss is selective or not.       The "Edge" Stimulus-Flicker Defined Form (FDF)   HEP uses a new stimulus-Flicker Defined Form (FDF)-which generates an illusory "edge" contour-a high temporal frequency driven illusory stimulus optimized for preferential stimulation of the magno-cellular system for early diagnosis and identification of diease progression. The two phases of the target are flickered in counterphase at 15 Hz to produce the illusory "edge" contour stimulus.   Open Platform   HEP makes it possible to explore new ideas. You can have access to the system to program your own stimuli and data analysis.   HEP visual field results join OHTS proven HRT structural analysis, giving a combined Structure-Function Map (SFM) in a single HEYEX (Heidelberg Eye Explorer) database and a single print out. By evaluating trend analyses of both structure and function, a rate of change may be confirmed at the early stages of the disease process. A measured rate of progression may help in the asessment of a patient's risk of vision loss and the decision to instigate or change treatment. The new Structure-Function Map helps our under-standing of glaucoma pathogenesis and improves clinical diagnosis and management.     Test in Normal Lighting Constant Fixation Monitoring Reat Time Display of Reliability Parameters Standard Automatic Perimetry Tests(40 dB to 12 dB sensitivity range) 24:2 full threshold, 24:2 screening, 19 point screening, Neurological tests, Driving test, Custom, Contrast sensivity, logMAR visual acuity charts (high and low contrast), FDF letter test.