Exercise ball Exercise ball An exercise ball, also known as a Swiss Ball, is a ball constructed of soft elastic with a diameter of approximately 35 to 85 centimeters (14 to 34 inches) and filled with air. The air pressure is changed by removing a valve stem and either filling with air or letting the ball deflate. It is most often used in physical therapy, athletic training and exercise. It can also be used for weight training. The ball, while often referred to as a Swiss ball, is also known by a number of different names, including balance ball, birth ball, body
Scioptic ball used simply as light sources. It was an early example of a type of wide-angle lens. Daniel Schwenter (1585-1636), professor of mathematics and oriental languages, developed the scioptic ball in 1636. In 1685, Johann Zahn illustrated a large workshop camera obscura for solar observations using the telescope and scioptic ball. Scioptic ball The scioptic ball is a universal joint allowing an optical instrument mounted on a ball to be swiveled to point anywhere in a wide arc. It was inspired by studies of the human eye. It has a number of applications. The scioptic ball may provide a firm anchor