BCC

Steps:
(1)Correct the refractive error of both eyes completely and adjust the pupil distance.
(2)Adjust the comprehensive optometer to the proximity pupil distance, pull down the proximity sight bar, and place the near cross vision card at 40cm from eye (the examination room is in dark lighting to prevent the pupil from shrinking under light and increase the focal depth, making it difficult for the examiner to recognize).
(3)Adjust the built-in accessory lens of the comprehensive optometer - cross cylinder lens to ± 0.50D.
(4)Make the patient report whether the horizontal line is clear or the vertical line is clear, or the horizontal and vertical lines are all clear.

Result Analysis:
1. If the horizontal line is clear, it proves that it is accommodation lags. Gradually increase the convex(+) sphere lens with + 0.25D as the first gear in front of both eyes until the horizontal and vertical lines are clear.
Record the added convex(+) sphere lens value, which is the accommodation lag;
2. If the vertical line is clear, it proves that it is accommodation lead. Gradually increase the concave(-) sphere lens with -0.25D as the first gear in front of both eyes until the horizontal and vertical lines are clear.
Record the added concave(-) sphere lens value, which is the accommodation lead;
3. 3. If the horizontal and vertical lines are all clear, it is proved that the eye accommodation reaction is equal to the accommodation stimulus.