A convolutional neural network model distinguishes eyelash images, break-up area images, non-break-up images, sclera images and eyelid images corresponding to a first prediction score, a second prediction score, a third prediction score, a fourth prediction score and a fifth prediction score to respectively produce a first label, a second label, a third label, a fourth label and a fifth label, thereby a break-up area can be detected in a tear film image and a tear film break-up time can be quantized for detection.
