Contrast Sensitivity Function


Contrast sensitivity technology assesses the quality of vision. Research shows that the standard visual acuity assessment only tests ones ability to see black on white high contrast letters. Many ocular and visual problems remain undetected when only high contrast vision is tested. Standard acuity measurement was originally designed as a tool to quantify optical blur and prescribe spectacles, it does not represent an accurate and representative measure of visual function in the real world. Contrast sensitivity measures the visual sensitivity at various contrast levels and can therefore detect and quantify visual performance problems better and at a much earlier stage than the standard visual acuity testing. Contrast sensitivity is particularly useful in documentation of visual performance in the presence of cataract and early detection of glaucomaand macular pathologies. It may be used to monitor treatment efficacy in glaucoma, cataracts, macular degeneration, and diabetic eye disease. It is a useful tool in understanding visual difficulties after all types of refractive surgery and contact lenses vision correction. 

Contrast Sensitivity Testing

Contrast sensitivity measures vision in the same way the auditory system is tested, by testing a range of different spatial frequencies or sizes at different contrast levels. This test provides a threshold measure at each spatial frequency. These thresholds are plotted to form a contrast sensitivity function curve, which is used a diagnostic representation of visual performance. The ability to test contrast sensitivity under standardized glare conditions enables your optometrist to understand and quantify how glare affects visual function in patients with cataracts and after refractive surgery. At Barnard and Levit we utilize the CSV1000E, manufactured by VectorVision USA. This is a research grade standardized and fully validated contrast sensitivity testing equipment. 

Contrast Sensitivity Function Graph

CSF graph