Abstract: A bimodal ethylene-co-1-hexene copolymer consisting essentially of a higher molecular weight component and a lower molecular weight component and, when in melted form at 190 degrees Celsius, is characterized by a unique melt property space defined by a combination of high-load melt index, melt flow ratio, and melt elasticity properties. A blown film consisting essentially of the bimodal ethylene-co-1-hexene copolymer. A method of synthesizing the bimodal ethylene-co-1-hexene copolymer. A method of making the blown film. A manufactured article comprising the bimodal ethylene-co-1-hexene copolymer.

Abstract: Apparatus and method provide for automatically measuring the refractive error of the human eye and thus the prescription for lens or eye glasses for correcting this error. Test symbols are alternately presented at two different locations on a test screen under control of a programmed automatic data processing system. The symbols are viewed by a subject through a lens system whose power may be continuously varied also under control of the data processing system. The data processing system also varies the size of the symbols presented to compensate for the power of the lens system so that a given symbol will appear to the subject to be of constant size. In one illustrative embodiment of the present invention, the subject communicates with the data processing equipment via a subject response device to indicate his preference for one or the other of the symbols presented at the two locations.