Certified Ophthalmic Technician (COT). The Certified Ophthalmic Technician is the second core designation level confirming knowledge in 19 specific content areas specifically designed to test the certified ophthalmic assistant or program graduate who intends to advance their career in the eye care field.
The original spinning jenny used eight spindles instead of the one found on the spinning wheel. A single wheel on the spinning jenny controlled eight spindles, which created a weave using eight threads spun from a corresponding set of rovings. Later models had up to one-hundred and twenty spindles.
This problem was resolved in 1764, when James Hargreaves invented a new machine that was capable of spinning eight threads of cotton yarn, instead of the spinning wheel's one. The new machine was called the spinning jenny.All this time the processes of spinning and weaving were still being carried out at home.his caused the fibers to be drawn out and twisted to make yarn. James Hargreaves was a weaver who lived in Stanhill, near Blackburn in Lancashire. He was poor, uneducated and had a large family. It is said that, in 1767, one of his daughters accidentally knocked over his spinning wheel.