Amsler grid Amsler grid The Amsler grid, used since 1945, is a grid of horizontal and vertical lines used to monitor a person's central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina, particularly the macula (e.g. macular degeneration, Epiretinal membrane), as well as the optic nerve and the visual pathway to the brain. In the test, the person looks with each eye separately at the small dot in the center of the grid. Patients with macular disease may see
Off-the-grid countries worldwide. In Africa, small and inexpensive pico solar electric lights and solar home systems are becoming readily available. Inexpensive solar panels, lithium ion batteries and high-efficiency LED lights make the systems affordable. Off-the-grid Off-the-grid is a system and lifestyle designed to help people function without the support of remote infrastructure, such as an electrical grid. In electricity, off-grid can be stand-alone power system or mini-grids typically to provide a smaller community with electricity. "Off-grid electrification" is an approach to access electricity used in countries and areas with little access to electricity, due to scattered or distant population. The term