Methods, systems, apparatuses, and/or devices for taking optical measurements. The methods, systems, apparatuses, and/or devices may include: emitting a first wavelength of light into the body； receiving light from a depth below a surface of the body corresponding to blood or sub-epidermis tissue of the body； and determining a physiological condition of the body when a current amount of light reflected or backscattered the blood or the sub-epidermis tissue and by the received by the optical sensor is different than a previous amount of light reflected or backscattered the blood or the sub-epidermis tissue and by the received by the optical sensor.
