Measurement of Local Strain Distribution and Its Variation Near Eyes During Blink Using Digital Image Correlation

The strain distribution of the facial skin surface at the local area near eyes at the instant of blinking are measured for evaluating the effect of cosmetics products. The motion of the skin at the local area as well as the whole face is observed using multiple digital high-speed cameras. Images of the typical blink motion are extracted from the mass of the local images by evaluating the blink motion in the whole face images. Two-dimensional digital image correlation is used for measuring strain. Irregularities and textures of the skin near the eyes are utilized as random patterns in digital image correlation. The strain distribution and its variation with time under various condition of skin such as bare skin, skin care, and foundation are obtained. The effect of cosmetic product on the skin behavior is elucidated by performing the series of the measurement for several subjects.