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.
1 Electricity is then taken through the lines to a pole transfomer â or a transformer box if underground â and pressure is lowered again to between 120 and 240 volts.  From here electricity comes into your home through a service box, where your meter is located to measure how much you use.