eye blinks detection from video frames

edit

is the method of LBP has good results ?

How this circle detects the eye ?

I'm a beginner in opencv , can you explain more ,

Thanks

Edited the answer..in the documentation you will find easy examples on how to use those functions, added links too ;-)

I have come up with this code , but I think it is not accurate , It can't track the eye when it moves in video

while(1)
{
    Mat frame,grey,edge,draw,src_gray,dst;
    cap >> frame; 
    cvtColor( frame, grey, CV_BGR2GRAY );
    GaussianBlur( grey, src_gray, Size(9, 9), 2, 2 );
    threshold(src_gray,dst, 0, 255, THRESH_BINARY);
    SimpleBlobDetector detector;
    std::vector<KeyPoint> keypoints;
   detector.detect(  dst, keypoints);
   Mat im_with_keypoints;
   drawKeypoints( grey, keypoints, im_with_keypoints, Scalar(0,0,255), DrawMatchesFlags::DRAW_RICH_KEYPOINTS )

Image 2Image 1

Can you post the video or the frame where you can't track it? I think you're blurring the image too much, Size(3,3) will be fine..If you are missing some part of the pupil (because of the led lights reflected i suppose) you can try to erode and then dilate the image after thresholding, or adjust the radius range..that should fix the problem since the pupil is always clearly visible with a close-up image like that

This is the video that I'm trying

video