Abnormal result:

(1) Scissor movement Two bands of light are seen in the pupil area, one moves

forward and the other moves backwards, such as scissors opening and closing,

due to lens tilt, corneal scars or irregular astigmatism in the examined eye.

(2) Spherical aberration and negative spherical aberration (caused by keratoconus).

People who need to be checked: patients with myopia or hyperopia and astigmatism.