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.
The spinning jenny used eight different spindles that were powered by a single wheel. This allowed one spinster to produce eight threads in the same amount of time it previously took to produce one. Later versions of the spinning jenny added even more lines which made the machine too large for home use.