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Norms and Forms

• Chart with approximate norms for Mars test scores. These norms have been collected from a variety of studies of letter contrast sensitivity, and from the clinical judgments of frequent users of the test including Drs. Eleanor E. Faye and Bruce Rosenthal.
• Mars Test Score Sheet (English)
• Mars Test Score Sheet (Spanish-Espanol)
• Mars Test Score Sheet (Chinese-Mandarin)
Order Form for fax or email orders

Literature about the test

• Arditi, A. (2004).Mars Letter Contrast Sensitivity Test White Paper. This brief paper is an introduction to letter contrast sensitivity testing that describes the main features of the Mars test and its uses in ophthalmology, optometry and visual disability determination.
• Arditi, A. (2005). Improving the Design of the Letter Contrast Sensitivity Test. Investigative Ophthalmology and Visual Science. 46(6), 2225-2229. This paper, published in June 2005, in ophthalmology's highest impact factor journal, describes the design of the test, and demonstrates why it has superior accuracy over other tests, yet maintains equivalence of scores obtained with the Pelli-Robson Contrast Sensitivity Chart.
• Dougherty, B.E., Flom, R.E. & Bullimore, M.A. (2005). An Evaluation of the Mars Letter Contrast Sensitivity Test, Optometry and Vision Science. 82(11), 970-975. This first, careful and quantitative evaluation of the validity and reliability of the Mars test was published in November 2005. Authored by Bradley Dougherty, Roanne Flom and Mark Bullimore, this study was performed at the Ohio State University Optometry School. The authors have no financial interest or connection with Mars Perceptrix.
• Haymes, S.A., Roberts, K.F., Cruess, A.F., Nicolela, M.T., LeBlanc, R.P., Ramsey, M.S., Chauhan, B.C. & Artes, P.H. (2006). The Letter Contrast Sensitivity Test: Clinical Evaluation of a New Design, Investigative Opthalmology and Visual Science. 47(6), 2739-2745. This second evaluation of the Mars test was published in June 2006. Conducted at the Medical School at Dalhousie University in Nova Scotia, the study found the Mars test to be valid, and reported equal or better test-retest reliability and slightly higher responsiveness (to detecting contrast sensitivity change after cataract surgery) than the Pelli-Robson Contrast Senstivity Test. They also found small but systematic differences in scores that suggest different normative values for the two tests (but see the Thayaparan et al. paper below for more on this!). The authors list no financial interest or connection with Mars Perceptrix.
• Thayaparan, K., Crossland, M.D. & Rubin, G.S. Clinical assessment of two novel contrast sensitivity charts. British Journal of Ophthalmolology, 91, 749-752, doi:10.1136/bjo.2006.109280. This most recent evaluation of the Mars test found the Mars test to have better repeatability (and hence accuracy) than the Pelli-Robson test, and good agreement between its scores and those of the Pelli-Robson. The paper also points out that small but systematic discrepancies between Mars scores and Pelli-Robson scores found by Haymes et al. (2006) are the result of an incorrect application of the Bland-Altman statistical analysis. The authors have no financial interest or connection with Mars Perceptrix.

Images

• Image (.gif) of Form 1 of the test with contrast boosted so all letters are visible (for PowerPoint and similar presentations)
• Hi-res image (.jpg) of Mars test with case and manual (for print presentations)
• Lo-res image (.jpg) of Mars test with case and manual (for PowerPoint and similar presentations)