The detection of eye blink plays a vital role in various applications of brain computer interface. The eye acts as a dipole consisting of the cornea and retina, wherein the cornea is much more positive than the retina providing typically around fewer microvolts to around 100mv between them. When the eyelid slides over an eye it acquires potential of an eye. This potential varies with various factors like light intensity, nature of blinking. This potential can be acquired using electrodes positioned near to the ocular region, which is connected to bio signal amplifier and filters for signal processing. The developed signal is connected as analog input to the Mini System Port(MSP) of connector C in Nl my RIO i.e. AI0/AI1. This has to be powered with external power supply and interfaced to a computer with USB. Fig.1
