Eye Extraction from a facial image in Python

import cv2

import numpy as np
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('rightEye.xml')
nose_cascade = cv2.CascadeClassifier('haarcascade_mcs_nose.xml')

img = cv2.imread('face.png')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
for (x,y,w,h) in faces:
    img = 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)
    src = roi_color[eyes[0,1]:eyes[0,1]+eyes[0,3], eyes[0,0]:eyes[0,0]+eyes[0,2]]
    cv2.imwrite('eye2.jpg', src)
    src = roi_color[eyes[1,1]:eyes[1,1]+eyes[1,3], eyes[1,0]:eyes[1,0]+eyes[1,2]]
    cv2.imwrite('eye3.jpg', src)