Methods and apparatus to count people are disclosed. An example apparatus includes a populator to populate a list with first characteristic datasets obtained from first image data representative of an environment during a first period of time, respective ones of the first characteristic datasets representative of a face detected in the environment during the first period of time; a comparator to compare the first characteristic datasets to each other to determine a first number of unique faces in the environment during the first period of time; and a discarder to delete the first characteristic datasets from the list when the first period of time has ended, the populator to re-populate the list with second characteristic datasets obtained from second image data representative of the environment during a second period of time subsequent to the first period of time.

The present disclosure relates to tools, kits, and methods for adjusting artificial eyelashes. The tool includes a body portion, a flange coupled to the body portion, and a plurality of indicia on the flange for measuring a lateral length of an individual's eyelashes.

A method of viewing a live image from a microscope through a camera lens of a first personal electronic device is described. The method includes receiving one or more optic powers of a microscope taking the live image entered into a first graphical user interface displayed on a screen of the first personal electronic device, and projecting a measurement tool on a second graphical user interface displayed on the screen of the first personal electronic device with units of measurement based on the entered optic powers. One or more non-transitory, computer-readable storage media and a computer or computer system are also described. Hardware designed to connect a personal electronic device such as a smartphone to a microscope for viewing of a live microscope image through the camera lens of the personal electronic device is also described.

A ruler includes an elongated base having a longitudinal axis, a first outer edge, and an opposite second outer edge. A scale is received by the base and is slidably positionable along the longitudinal axis to a plurality of detent positions. The scale includes indicia depicting both fractional and decimal portions of one inch.

A digital tape measure device is configured with an optical encoder that facilitates improved measurement capabilities. The optical encoder may be configured in one of several different optical configurations to process differential signaling generated by light generating and detecting elements in the sensor.