Welch Allyn SureSight Vision Screener - User Manual - Manual (Page 22)

18
Approximate Relationship of Sphere to Visual Acuity
00 Ages 5-15
Referral Criteria
Readings outside the normal limits should be confirmed prior to referral.
It is recommended that referral criteria be agreed upon between you and the eye
care specialist receiving your referrals.
With adults, it is suggested that the eye chart be used to confirm any apparent
reading outside the normal limits.
Negative (-) Diopters
Myopia (Near-
Sightedness)
Positive (+) Diopters
Hyperopia (Far-
Sightedness)
00
0.0 20/20 0.0 20/20
-0.5 20/30-40 +1.0 20/20
-0.8 20/50 +2.0 20/20
-1.0 20/60 +3.0 20/25
-1.25 20/70 +3.25 20/30
-1.75 20/100 +3.75 20/40
-2.0 20/200 +4.0 20/40-50
-3.0 20/285 +4.3 20/50
-4.0 20/420 +5.0 20/70
-5.0 20/565
6 Months 3-5 years* Adults (>10 years)
Sphere <-2.0 or >+3.5 <- 1.0 or > +2.0 <- 1.0 or > +2.0
Cylinder ----- > 1.0 > 1.0
Difference >1.5 > 1.0 -----