Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
X-axis: The efficiency of cylinder degree correction; Y-axis: Various follow-up visits; Group A: Cylinder degree range of -0.75 to -0.50 D; Group B: Cylinder degree range of -1.75 to -1.00 D; Group C: Cylinder degree ≤-2.00 D.
