Rod cell Rod cell Rod cells are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision. On average, there are approximately 90 million rod cells in the human retina. Rod cells are more sensitive than cone cells and are almost entirely responsible for night vision. However, rods have little role in color vision, which is the main reason why colors are much less apparent in dim light, and not
Optical stretcher stretcher, it was also shown that cancerous cells differ significantly in their mechanical properties from their healthy counterparts. The authors claim that the 'optical deformability' can be used as a biomechanical marker to distinguish cancerous from healthy cells, and even that higher stages of malignancy can be detected. A typical optical stretcher setup consists of the following main parts: Objects trapped in the optical stretcher usually have diameters on the scale of 10 micrometer, which is very large compared to the laser wavelengths used (often 1064 nm). It is thus sufficient to consider the interaction with the laser light in