CRAO is considered a stroke of the eye. Studies show that about two-thirds of patients have underlying high blood pressure and one-fourth of patients will have significant carotid artery disease (plaque with narrowing of the artery lining), cardiac valvular disease or diabetes.
Electrical pressure is measured in volts, or voltage. All electrical devices are rated for specific voltages. Most devices and small appliances in a home are rated for 120 volts, while high-voltage appliances, such as electric dryers, ranges, and many baseboard heaters, are rated for 240 volts.
A typical US household voltage is 120/240 V, 60 hz, single phase. There is a tolerance and the actual measured voltage is rarely exactly 120 volts. A common reading at my house is 117 volts. Industrial motors are made and rated in multiples of 115V (115, 230, 460, and 550Vac) for use on line voltages in multiples of 120 V (120, 240, 480, and 600 Vac).