Image Stabilized Binoculars
Image stabilized binoculars are increasingly used by astronomers and boating enthusiasts as modern IS binoculars do a great job in eliminating the natural shake experienced when using hand-held binoculars.
Hand shake combined with a vessels natural movement can make it really difficult to read detail such as the names of nearby boats. Astronomers trying to focus on faraway targets generally have to use tripods as the slightest hand shake make a huge difference to the image in view at the vast distances involved. Hand shake is manageable with lighter and lower power binoculars but at higher powers and accompanying heavier weights it becomes a huge issue.
Image stabilization aims at adjusting the image instantly to compensate for the shake and keep the image stable in your view. Actively stabilized binoculars use electronics and gyros to sense the amount of roll and shake and adjust the angle of the lens groups or prisms to offset the movement. Passive stabilized binoculars have floating prisms balanced by magnets. With stabilization, higher magnification than usual is easily manageable even with small diameter lenses.