Blur sensitivity in myopes.
OBJECTIVE
This study compared the ability of myopes and emmetropes to detect subjectively the presence of retinal defocus.


METHODS
Subjects (12 myopes, 12 emmetropes) were cyclopleged and monocularly viewed a bipartite target through an appropriate near addition lens via a 2-mm artificial pupil. One-half of the target remained fixed while the other half was alternatively moved forward or backward until subjects first reported a difference in clarity between the two halves of the target.


RESULTS
The mean blur threshold for the emmetropes and myopes was +/-0.11 and +/-0.19 D, respectively (p = 0.0001).


CONCLUSIONS
These results demonstrate that myopes are less sensitive to the presence of blur, and may at least partially explain why previous reports have demonstrated a larger lag of accommodation in this refractive group. Additionally, the hyperopic retinal defocus resulting from the increased accommodative error may play a significant role in myopia development and progression.
Rosenfield
M
M
State University of New York, College of Optometry, New York 10010, USA. Rosenfield@sunyopt.edu
Abraham-Cohen
J A
JA
D000065:Accommodation, Ocular; D000328:Adult; D015350:Contrast Sensitivity; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D009216:Myopia / Q000503:physiopathology*; D012160:Retina / Q000503:physiopathology*