The answer
In NIDEK TONOREF II AR/KM measurement, BLK means blinking or slight movement, ALM means improper focusing, FAR and NEAR identify focus distance errors, and +OVR, -OVR and COVR mean the corresponding measurement range was exceeded. Stop blinking or moving, correct focus, or repeat the measurement as appropriate.
Filed under Error codes
These messages identify different causes of an unusable AR or KM result:
BLK: blinking or slight movement made measurement impossible; repeat after the eye is still.ALM: focusing is not proper; focus and measure again.FAR: the eye is too far from the device during KM measurement.NEAR: the eye is too close during KM measurement.+OVRor-OVR: the spherical power or corneal curvature radius exceeds the positive or negative measurable limit.COVR: cylindrical power exceeds its measurable limit.
If the device loses alignment or focus during a measurement, the operation is interrupted. Press the start button to continue; the new results are added to the earlier stored results.
