a system rapidly and accurately assesses the lachrymal fluid content in a person &# 39 ; s eye which minimizes patient discomfort . the preferred system includes a fluid sampling device and an assessment device . the preferred sampling device includes a lachrymal fluid absorbent sample pad and a non - absorbent handle . the preferred assessment device includes a receiver for receiving a lachrymal fluid sample pad and includes a control circuit coupled with the receiver for determining the electrical capacitance of the pad which capacitance varies in accordance with variations in lachrymal fluid content , and for producing an output correlated with the lachrymal fluid quantity in the pad .