HKhai (M/21) came for eye examination, with complaint of glaring & difficulty driving at night.. daytime driving is fine. He reported that his glasses were of astigmatism correction & he wore them during night driving & using computer only.
Vision without glasses
R: 6/7.5-
L: 6/7.5-
Examination shows: (Delay Fogging)
R: +0.25/-0.50×90 (6/6) [+1.00 blur lens test: 6/7.5-]
L: PL/-0.50×80 (6/6) [+1.00 blur lens test: 6/18-] [L: left dominant eye] L>R
Add: +0.50 (R>L)
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test, CT)
NMD @Distance
(alternating CT: upon covering left eye, patient reported the target goes to his left.. when covering right eye, the target goes to his right)
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
Near: 4 – 6 XP (blue part)
+1.00 Near: : 8 XP (blue part)
-1.00 Near: : 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
+1.50
(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: +0.25
L: PL
(normal value: +0.25 to +0.75)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
6/8cm, 8/12cm, 10/14cm, 12/16cm, 14/18cm
(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: 20 YO, 20 YO, 20 YO (target is blurry @end of RAF rule, only comes into focus starting @35cm)
L: 20 YO, 20 YO, 20 YO
(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 +/- 1.50
BE: 9 cycle per minit(cpm), difficult with minus lens(2nd lens)
R: 10 cycle per minit(cpm), difficult with minus lens(2nd lens) (both eyes see better than with right eye)
L: 9 cycle per minit(cpm), difficult with plus lens(1st lens) (left eye sees better than with both eyes)
– cannot clear -2.00
(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/6/4
Near, Base-In/Divergent, NFV: 4/10/8
Distance, Base-In/Divergent, NFV: 8/10/6
Distance, Base-Out/Convergent, PFV: 14/20/18
(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: 14 cpm
Distance: 14 cpm
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar (with 1Base In OU)
Near, Base-Out/Convergent, PFV: x/10/6
Near, Base-In/Divergent, NFV: 4/20/16
Near vision with 1Base In OU is not preferred
All near tests are done without Add.
Interpupillary distance, IPD = 6.8cm
We asked if Khai has any complaint on near, he said that his near vision is fine. His work is mostly on the move, so he does not use digital devices extensively daily.