eyeball. 1  Photoreceptors are the cells in the retina that respond to light. Their distinguishing feature is the presence of large amounts of tightly packed membrane that contains the photopigment rhodopsin or a related molecule.
In chemical analysis,  matrix refers to the components of a sample other than the analyte of interest. The matrix can have a considerable effect on the way the analysis is conducted and the quality of the results obtained; such effects are called matrix effects. For example, the ionic strength of the solution can have an effect on the activity coefficients of the analytes.
â¢ MATRIX (noun) The noun MATRIX has 5 senses: 1. a rectangular array of elements (or entries) set out by rows and columns. 2. an enclosure within which something originates or develops (from the Latin for womb) 3. the body substance in which tissue cells are embedded. 4. the formative tissue at the base of a nail.