基于cv2的Python眼睛检测

我用Python编写了以下代码来识别图片中的眼睛， 但它也能识别其他事物如眼睛，如鼻孔、嘴角等。 我该怎么办

import cv2

face_cascade = cv2.CascadeClassifier('./haar cascade files/haarcascade_frontalface_alt.xml')
eye_cascade = cv2.CascadeClassifier('./haar cascade files/haarcascade_eye.xml')


img = cv2.imread('hi.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)

for (x,y,w,h) in faces:
   cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)

   roi_gray = gray[y:y+h, x:x+w]
   roi_color = img[y:y+h, x:x+w]
   eyes = eye_cascade.detectMultiScale(roi_gray)
   for (ex,ey,ew,eh) in eyes:
      cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)

cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()