Alvin (M/32) came for eye examination, with complaint of slight blurry far vision with existing glasses of 2years. Near vision is fine but he has tired eyes upon prolonged near work.
Vision without glasses
R: 6/45
L: 6/18
Vision with existing glasses of 2years
R: -2.00/-0.50×45 (6/9-)
L: -1.50 (6/6)
Examination shows: (Delay Fogging)
R: -2.75 (6/6) [+1.00 blur lens test: 6/9-] (R: right dominant eye) R>L
L: -1.50 (6/6) [+1.00 blur lens test: 6/9-]
Add: +0.75 L>R
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test, CT)
NMD @Distance
small XP, fast recovery @Near
(alternating CT: upon covering left eye, patient reported the target goes to his left. when covering right eye, the target goes to his right)
(normal value: orthophoria/NMD-No Movement Detected or small XP, fast recovery)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
Examination of Eye Alignment/Posture (Howell Card) by 6^ Base Down on Right eye
Distance: 0 – 2 XP (blue part)
Near: 8 XP (blue part)
+1.00 Near: 12 XP (blue part)
-1.00 Near: 0 – 2 XP (blue part)
(normal value: 0-1 EP (yellow part) or 0-3 XP (blue part) @Distance; and 0-6 XP (blue part) @Near)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+2.00
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
-0.25
(normal value: -1.37 to -3.37)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: +1.00
L: +1.00
(normal value: +0.25 to +0.75)
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 31 YO, 31 YO, 31 YO
L: 31 YO, 31 YO, 31 YO
(normal value: AA goes according to age; YO=years old)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
7/12cm, 7/12cm, 7/12cm, 8/14cm, 8/14cm, 8/14cm
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
Accommodation Facility – ability to change focus: far to near or near to far (by Flipper +/-1.00)
BE: 12 cycle per minit(cpm), difficult with minus lens(2nd lens)
R: 11 cycle per minit(cpm), difficult with minus lens(2nd lens) [both eyes see better than with right eye]
L: 12 cycle per minit(cpm), difficult with minus lens(2nd lens) [both eyes see better than with left eye] R: +0.75
– cannot clear -2.00 & -1.50
(normal value: 1 cycle = 2 words read
Monocular or R/L: 6cpm to 16cpm
Binocular or BE-both eyes: 4cpm to 14cpm)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar
Near, Base-Out/Convergent, PFV: x/25/18
Near, Base-In/Divergent, NFV: 18/25/20
Distance, Base-Out/Convergent, PFV: x/14/12
Distance, Base-In/Divergent, NFV: x/10/8
(normal value: Blur/Break/Recovery)
Near, PFV: 10-28/7-21
Near, NFV: 7-19/5-15
Distance, PFV: 4-18/5-9
Distance, NFV: 4-10/2-6
[Scheiman et al – Adult Data]
Vergence Facility – ability to make rapid repetitive vergence changes (by Prism Flipper of 12Base Out & 3Base In)
Near: 8 cpm (double with Base Out initially, then can see single)
Distance: 11 cpm (double with Base Out initially, then can see single)
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Interpupillary distance, IPD = 6.6cm