Table 2.

Criteria for assessing the lens movement

Grade	Descriptor	Explanation
-2	Extremely inadequate	The lens does not move on blink.
-1	Slightly inadequate	The lens moves less than 0.2 mm on blink.
0	Optimal	The lens moves 0.2-0.4 mm on blink
+1	Slightly excessive	The lens moves more than 0.4 but less than 1.0 mm on blink.
+2	Extremely excessive	The lens moves more than 1.0 mm on blink