Although eye charts can provide a quick assessment of spatial resolution, they often miss significant losses in contrast sensitivity caused by retinal dysfunctions occurring in the peripheral visual field or due to more general ophthalmological or neurological disorders2,3.
For a more detailed characterisation of spatial visual abilities, contrast letter charts and measurements of contrast sensitivity are more informative.
Provides more information over a large range of spatial frequencies, including precise measurements relative to the CSF peak and cut-off frequency of the central or peripheral visual field.
Quick, easy and efficient to score, this Pelli- Robson4 style test measures contrast acuity using customised spatial frequencies over a fine contrast range.
3Russell et al., Clinical and Experimental Optometry 1995 (78)2: 43-57
4Pelli et al., Clinical Vision Science 1988 (2)3:187-199