Operation essentials: clear focus, moderate brightness, adjust the slit width and irradiation angle at the right time. Standard operation: Adjust the instrument handle with the right hand and prop up or turn over the eyelid of the examined eye with the left hand. Scope of application: Observe the eyelid, conjunctiva, cornea, sclera, anterior chamber, iris, pupil, lens and anterior 1/3 vitreous. Usage: 1. Preparation: fix the patient’s head on the jaw rest and frontal rest, adjust the height of the elevating table and jaw rest so that the patient’s outer canthus is at the same height as the engraved line on the column. Turn on the slit lamp and camera power, and move the resulting slit to the patient’s nasal bridge to adjust the focus so that the image is clear. 2, external eye photography: slit lamp arm and microscope arm into 45º angle, focus precisely on the central corneal surface of the pupil, add hairy glass, fully open the slit, low magnification (6.4*) for observation and photography. 3, anterior chamber depth photography: slit lamp arm and microscope arm into 45º angle, focus precisely on the central pupil corneal surface, slit off to the narrowest degree, forward lightly move the slit lamp arm, see the corneal anterior, middle and posterior three layers of structure clear, observe and take pictures. 4.Cataract photography 4.1.Diffuse light crystallography: suitable for cortical cataract with visual acuity ≤0.1. The slit lamp arm is at 45ºangle with the microscope arm, the focal point is precisely aligned with the anterior crystal cortex of the central pupil, hairy glass is added, the slit is fully opened, and observation and photography are performed under low magnification (6.4*). 4.2, Slit light crystallography: cortical cataract and nuclear cataract with visual acuity > 0.1. The slit lamp arm is at 45-60ºangle with the microscope arm, the focus is precisely aligned with the temporal pupil margin (3:00), the slit transitions slowly from the narrowest to the wide slit, and when the crystal layered structure is seen to be clear and the pupil area is filled with images, photographs are taken. 4.3. Diffusion + slit crystal photography: Patients with posterior subcapsular cataract with mild cortical and nuclear opacities but poor visual acuity. The pupil must be dilated with Medori eye water (5min/time*2), the slit lamp arm is at 45ºangle with the microscope arm, the focal point is aligned with the central posterior crystal cortex of the pupil, the hair glass is added, the slit is fully opened, and observation and photography are performed at low magnification (6.4*); at the same time, the hair glass is put down, the slit is narrowed, and the posterior capsule of the crystal is fully displayed for photography. Note: 1. The photographic environment should be a dark room as much as possible to avoid direct sunlight on the patient’s eye; 2. The luminance of the slit should be moderate to show the lesion clearly, avoiding too strong light to narrow the pupil; 3. The cornea or crystal should be shown in the center of the photo, do not deviate from the side or omit the lesion; 4. Accurately record the serial number of the photo and the patient’s information, and upload the copy in time.