Eye chart number). The denominator indicates the distance in feet at which a person with normal vision could stand to correctly identify the same symbols identified by the person tested. For example, a visual acuity of 20/20 is considered normal. Numerous types of eye charts exist and are used in various situations. For example, the Snellen chart is designed for use at 6 meters or 20 feet, and is thus appropriate for testing distance vision. There is often also a need to test a subject's vision at near or occupational tasks (such as reading or computer use). For these situations, a Rosenbaum
The Name of the Doctor looks forward and back". On 12 May 2013, a week before the official premiere of "The Name of The Doctor", it was announced that 210 "Doctor Who" fans in the United States had received their Blu-ray box set of the second half of the seventh series early due to a production error. After successfully requesting that they not reveal the plot, the BBC sent the recipients copies of an interview with the cast. Moffat later complimented the "210 of them, with the top secret episode in their grasp – and because we asked nicely, they didn't breathe a word." "The