I am looking for a way to quantify "visual capacity".
In our paper (http://www.frontiersin.org/psychopathology/10.3389/fpsyg.2013.00352/abstract), we define visual capacity as a conglomeration of the following visual skills:
visual acuity, visual sensitivity to light (contrast sensitivity), motion sensitivity, color sensitivity, visual field size, binocularity & stereoscopic vision?
My questions concerning this matter are:
1) Is this an exhaustive list - probably not - but what is missing?
2) How can one effectively (fast, easy, cheap) measure the following constructs in a given individual:
2a) visual acuity?
2b) visual sensitivity to light (contrast sensitivity)?
2c) motion sensitivity?
2d) color sensitivity?
2e) visual field size?
2f) binocularity?
2g) stereoscopic vision?
3) Is there already some research on what constitutes "very good vision"?
Thank you for your support!
I think your local Orthoptic department would be able to assess all that you have described. It’s an interesting question & I will be intrigued to see what people think. My thoughts are that each component has it's own tests with normative values, i've not come across a 'visual capacity score' as yet:
1. Visual Acuity: the present gold standard is considered the crowded LogMAR chart (EDTRS)
2. Contrast Sensitivity: the Pelli-Robson chart is quick and easy.
3. Colour vision: Ishihara is commonly used; however there are lots of options including the 100 hue test of which there is a free version online: http://www.xrite.com/online-color-test-challenge
4. Visual field: The Goldmann Perimeter or the Octopus 900 are considered the most accurate (these are kinetic visual field analysers – moving target)
5. Binocular single vision (BSV):
1 Sensory Fusion (bagolini glasses/worth lights)
2 Motor Fusion (Prism fusion range)
3 Steropsis (Frisby stereoacuity test)
6. You could also consider ocular motility? Recording a field of BSV, and quantifying this using the Woodruff scale?
I have never read on "visual capacity scores" but I am sure someone investigated this before... as most of the things....
But something I can figure out similar are the number of publications and studies analysing and reporting "quality of vision" "quality of life" through questionnaire markers and they link and multivariate correlate the questionnaire scores (after good psychometric validated evaluation of the questionnaires) to some or all of the individual metrics you propose (and may extend).
Once you have this for a large population, you can validate the predictive model based on the multicorrelations against a new population using the same questionnaire, once this is done with good level of accuracy, you can predict with this a kind of "visual capacity score"
Sorry if my explanation is not very clear or easy to follow but I hope it helps
some references:
Comparison of visual performance of multifocal intraocular lenses with same material monofocal intraocular lenses. Yamauchi T, Tabuchi H, Takase K, Ohsugi H, Ohara Z, Kiuchi Y. PLoS One. 2013 Jun 28;8(6):e68236. doi: 10.1371/journal.pone.0068236. Print 2013.
Dry Eye Disease: Impact on Quality of Life and Vision. Uchino M, Schaumberg DA. Curr Ophthalmol Rep. 2013 Jun;1(2):51-57.
Visual function after bilateral implantation of a new zonal refractive aspheric multifocal intraocular lens. Muñoz G, Albarrán-Diego C, Ferrer-Blasco T, Sakla HF, García-Lázaro S. J Cataract Refract Surg. 2011 Nov;37(11):2043-52. doi: 10.1016/j.jcrs.2011.05.045.
Evaluation of the relationship between quality of vision and visual function in Japanese glaucoma patients. Sawada H, Fukuchi T, Abe H. Clin Ophthalmol. 2011;5:259-67
Identifying Content for the Glaucoma-specific Item Bank to Measure Quality-of-life Parameters. Khadka J, McAlinden C, Craig JE, Fenwick EK, Lamoureux EL, Pesudovs K. J Glaucoma. 2013 Apr 2. [Epub ahead of print]
Subjective quality of vision before and after cataract surgery. Skiadaresi E, McAlinden C, Pesudovs K, Polizzi S, Khadka J, Ravalico G. Arch Ophthalmol. 2012 Nov;130(11):1377-82. doi: 10.1001/archophthalmol.2012.1603.
Psychometric properties of the NEI-RQL-42 questionnaire in keratoconus. McAlinden C, Khadka J, de Freitas Santos Paranhos J, Schor P, Pesudovs K. Invest Ophthalmol Vis Sci. 2012 Oct 25;53(11):7370-4. doi: 10.1167/iovs.12-9969.
The importance of rating scales in measuring patient-reported outcomes. Khadka J, Gothwal VK, McAlinden C, Lamoureux EL, Pesudovs K. Health Qual Life Outcomes. 2012 Jul 13;10:80. doi: 10.1186/1477-7525-10-80.
A head-to-head comparison of 16 cataract surgery outcome questionnaires. McAlinden C, Gothwal VK, Khadka J, Wright TA, Lamoureux EL, Pesudovs K. Ophthalmology. 2011 Dec;118(12):2374-81. doi: 10.1016/j.ophtha.2011.06.008. Epub 2011 Sep 25.
Reengineering the glaucoma quality of life-15 questionnaire with rasch analysis. Khadka J, Pesudovs K, McAlinden C, Vogel M, Kernt M, Hirneiss C. Invest Ophthalmol Vis Sci. 2011 Sep 1;52(9):6971-7. doi: 10.1167/iovs.11-7423.
Improvements in visual ability with first-eye, second-eye, and bilateral cataract surgery measured with the visual symptoms and quality of life questionnaire. Gothwal VK, Wright TA, Lamoureux EL, Khadka J, McAlinden C, Pesudovs K. J Cataract Refract Surg. 2011 Jul;37(7):1208-16. doi: 10.1016/j.jcrs.2011.01.028.
Subscale assessment of the NEI-RQL-42 questionnaire with Rasch analysis. McAlinden C, Skiadaresi E, Moore J, Pesudovs K. Invest Ophthalmol Vis Sci. 2011 Jul 29;52(8):5685-94. doi: 10.1167/iovs.10-67951.
Multifocal intraocular lens with a surface-embedded near section: Short-term clinical outcomes. McAlinden C, Moore JE. J Cataract Refract Surg. 2011 Mar;37(3):441-5. doi: 10.1016/j.jcrs.2010.08.055.
The development of an instrument to measure quality of vision: the Quality of Vision (QoV) questionnaire. McAlinden C, Pesudovs K, Moore JE. Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5537-45
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