def calc_eye_close_ratio(lmk: np.ndarray, target_eye_ratio: np.ndarray = None) -> np.ndarray:
    """
    Calculate the eye-close ratio for left and right eyes.

    Parameters:
    lmk (np.ndarray): Landmarks array of shape (B, N, 2).
    target_eye_ratio (np.ndarray, optional): Additional target eye ratio array to include.

    Returns:
    np.ndarray: Concatenated eye-close ratios.
    """
    lefteye_close_ratio = calculate_distance_ratio(lmk, 6, 18, 0, 12)
    righteye_close_ratio = calculate_distance_ratio(lmk, 30, 42, 24, 36)
    if target_eye_ratio is not None:
        return np.concatenate([lefteye_close_ratio, righteye_close_ratio, target_eye_ratio], axis=1)
    else:
        return np.concatenate([lefteye_close_ratio, righteye_close_ratio], axis=1)

    Calculate the eye-close ratio for left and right eyes.

    Parameters:
    lmk (np.ndarray): Landmarks array of shape (B, N, 2).
    target_eye_ratio (np.ndarray, optional): Additional target eye ratio array to include.

    Returns:
    np.ndarray: Concatenated eye-close ratios.
    
liveportrait/utils/retargeting_utils.py