The scientific definition of hardness is the ability to resist scratching, nothing more. If you ask most folks, theyâll say feathers are soft and glass is hard. In the world of gemology, however, glass is fairly soft. It can be scratched easily by a variety of what we gemologists consider hard substances.
convergence excess. Convergence excess is an over-convergence of the eyes at a near distance for extended periods of time, such as when reading, writing, drawing, or viewing a computer screen. Sometimes, the over-convergence can result in diplopia (double vision).nce a diagnosis of convergence insufficiency has been made, a simple visual therapy technique that may be helpful is pencil pushups. 1. Hold a pencil at arm s length, with the eraser about level with the tip of your nose.
Oh, and there will be a quiz in class. Click the link below for slides, a handout version of the slides, and links to interesting articles. Definition. Convergence, as used in the theory of economic growth, refers to the tendency of less developed economies to grow more quickly than more mature economies. . The theory is based on the idea that the growth rate will slow as an economy approaches the steady state level of capital per worker.