I. Introduction
Progressive loss of the field of vision is characteristic of a number of eye diseases such as glaucoma, a leading cause of irreversible blindness in the world. Recently, there has been an explosion in the amount of data being stored on patients who suffer from visual deterioration, including visual field (VF) tests, retinal images [1], and perhaps, in the not too distant future, even continuous intraocular pressure measurements [2]. The aim now is to extract as much information as possible from these data in order to address fundamental questions still open within the glaucoma research community. The VF test assesses the sensitivity of the retina to light. It is typically measured by automated perimetry, a technique in which the subject views a dim background as brighter spots of light are shone onto the background at various locations in a regular grid pattern. The brightness at which the subject sees the spots of light is related to the retinal sensitivity. There are many diseases and conditions that affect the VF, the most common being the optic neuropathy “glaucoma,” neurological, and retinal diseases. Early detection of glaucoma as well as other conditions and diseases that cause visual impairment is invaluable as early intervention can slow VF deterioration.