Eye chart smaller symbols until the person cannot identify the symbols. The smallest symbols that can be reliably identified is considered the person's visual acuity. The Snellen chart is the most widely used. Alternative types of eye charts include the logMAR chart, Landolt C, E chart, Lea test, Golovin–Sivtsev table, the Rosenbaum chart, and the Jaeger chart. Charts display several rows of optotypes, which are standardized symbols for testing vision. Optotypes are usually letters, numbers, or geometric symbols. Each row of the chart depicts optotypes of a different size. Typically the largest optotypes are in the top row. The optotypes become progressively
The Name of the Doctor to kill the Doctor's allies unless the Doctor says his name to unlock the TARDIS doors. The Doctor refuses, but as he speaks, River says the Doctor's name and unlocks the TARDIS. Inside, the Doctor reveals a pulsating column of light to be his time stream. The Great Intelligence enters it in order to undo the Doctor's past as revenge for all the defeats it has been dealt. The positive effects of the Doctor's travels begin to be nullified by the Intelligence's interference. Jenny and Strax both disappear. Clara remembers the Doctor telling her that she has helped the Doctor