Irradiation dose to the lens of the eye during CT of the head.

The irradiation dose to the lens of the eye during CT scanning has been measured in 16 patients. The dose is greatly influenced by changes in gantry angulation, the position of the patient, the thickness and number of slices, KV, and milliamperage. The total lens dose has been measured to be higher than previously reported. Repeated CT scans imply the risk of irradiation cataract, especially in infants and children.