Mr Pang (M/50) came for eye examination, with complaint of slight blurry near vision with his reading glasses.. he is unable to see smaller print & sometimes glaring with light.. eg there is a LED light at living room that he finds uncomfortable at times. He did wear glasses for far vision 5years ago, he lost it & he did not make new ones.
Vision without glasses
R: cannot guess 6/12-
L: cannot guess 6/12-
Existing ready-made reading glasses
R: +2.50
L: +2.50
Examination shows: (Delay Fogging)
R: +1.25/-0.75×5 (6/7.5) PHNI
L: +1.00/-0.75×170 (6/6) [+1.00 blur lens test: 6/7.5-] (L: left dominant eye)
Add: +2.00
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 – 2 XP (blue part)
Near: 16 XP (blue part)
-1.00 Near: 14 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
-0.50
(normal value: -1.37 to -3.37)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
14/20cm, 20/28cm, 22/34cm, 14/20cm, 20/28cm, 20/28cm
(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
R: target is clearer with -0.75DC than -0.50DC
L: target is clearer with -0.75DC than -0.50DC
(normal value: AA goes according to age; YO=years old)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: dim
L: +0.25
(normal value: +0.25 to +0.75)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar
Near, Base-Out/Convergent, PFV: x/20/16
Near, Base-In/Divergent, NFV: x/14/12
Distance, Base-Out/Convergent, PFV: 12/20/18
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: 9 cpm (double with Base Out, blink eyes & single swiftly)
Distance: 12 cpm
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Fluorescein (assess integrity of front surface of eye, cornea)
R: -ve staining
L: -ve staining
All near tests are done with Add.
Interpupillary distance, IPD =6.8cm
Mr Pang said that he does lose focus when doing near work in which he will take a break & walk around before returning to his computer. His vergence is fine, he needs more longsighted power to sustain his near work.
