Elva (F/14) came for eye examination, with complaint of slight blurry when looking back at far after seeing near.. eg. when she copies from whiteboard at school.
Vision without glasses
R: 6/60
L: 6/45
Vision with existing glasses of 2-3years
R: -4.75/-1.25×180 (6/6-)
L: -2.75/-1.00×180 (6/9-)
Add: +1.00
Examination shows: (Delay Fogging)
R: -4.50/-1.25×180 (6/6) [+1.00 blur lens test: 6/9+] [R: right dominant eye]
L: -2.25/-1.25×10 (6/6) [+1.00 blur lens test: 6/12-]
Add: +0.50 (sometimes favoured, sometimes not)
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test, CT)
NMD @Distance
(alternating CT: upon covering left eye, patient reported the target stays centre.. when covering right eye, the target goes to her right)
NMD @Near
(alternating CT: upon covering left eye, patient reported the target goes to her left.. when covering right eye, the target goes to her 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: 2 – 4 XP (blue part)
+1.00 Near: : 4 – 6 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
+1.25
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
-0.75
(normal value: -1.37 to -3.37)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: +0.50 (reflex very dim)
L: +0.50 (reflex very dim)
(normal value: +0.25 to +0.75)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
TTN, TTN, TTN, TTN, 8/12cm, 10/14cm
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 6 YO, 6 YO, 6 YO (target is blurry @end of RAF rule, only comes into focus starting @34cm)
L: 20 YO, 15 YO, 20 YO (target is blurry @end of RAF rule, only comes into focus starting @26cm)
(normal value: AA goes according to age; YO=years old)
Facility (Accommodation facility – ability to change focus: far to near or near to far) by Flipper +/- 1.00
BE: 9 cycle per minit(cpm), difficult with minus lens(2nd lens)
R: 8 cycle per minit(cpm), difficult with minus lens(2nd lens) (both eyes see better than with right eye)
L: 4 cycle per minit(cpm), difficult with minus lens(2nd lens) (both eyes see better than with left eye)
– 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/20/18
Near, Base-In/Divergent, NFV: x/18/14
Distance, Base-Out/Convergent, PFV: x/25/20
Distance, Base-In/Divergent, NFV: x/12/10
(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: 4 cpm (double Base Out, blink2 eyes single.. then double Base In, blink2 eyes single)
Distance: 9 cpm
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule (with Add +0.75)
18/28cm, 18/28cm, 18/28cm
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule (with Add +0.75 is favoured monocularly)
R: 6 YO, 6 YO, 6 YO (target is blurry @end of RAF rule, only comes into focus starting @38cm then 34cm)
L: 15 YO, 25 YO, 15 YO (target is blurry @end of RAF rule, only comes into focus starting @36cm then 30cm)
(normal value: AA goes according to age; YO=years old)
Interpupillary distance, IPD = 6.3cm
Elva wants to wear contact lens now due to sports.
*Updated
Contact lens (1st)
R: -4.00/-1.25×180
L: -2.25/-1.25×10
VA OU: 6/6
Over Rx (Far)
R: +0.50 R>L (+0.75 L>R)
L: PL
Over Rx (Near)
R: PL
L: +0.25 (L>R)
Prescribe (2nd)
R: -3.75/-1.25×180
L: -2.00/-1.25×10
Elva did not like the 2nd reduced power, she prefers the 1st power.