Contrast Sensitivity Test
Clinical-grade Pelli-Robson benchmark for visual health.
Technical & Clinical Overview
The Pelli-Robson Contrast Sensitivity Test is the medical standard for evaluating how well a patient can distinguish objects from their background. While visual acuity (Snellen) measures the size of letters, contrast sensitivity measures the faintness of letters, providing a more comprehensive view of functional vision.
VCS Testing and Mold Exposure
Increasingly, Visual Contrast Sensitivity (VCS) tests are used by clinicians as a biomarker for neurotoxicity. Chronic exposure to certain indoor molds, biotoxins, and environmental neurotoxins can lead to a measurable reduction in mid-spatial frequency contrast sensitivity.
Our online VCS test follows the 0.15 Log CS step progression used in clinical Pelli-Robson charts, providing a reliable screening tool for individuals monitoring changes in their vision due to health or environmental factors.
Interpreting Your Results
Contrast sensitivity is reported as the Log Contrast Sensitivity (Log CS) score. A higher score indicates better retinal health and neural processing of visual information.
Pelli-Robson vs Mars Chart
Both the Pelli-Robson and the Mars Contrast Sensitivity Test measure a patient's threshold using Sloan letters. However, the Pelli-Robson chart is typically viewed from 1 meter and uses fixed size triplets, whereas the Mars test is designed for near-vision (handheld) and decreases contrast on a per-letter basis. Our Vision Lab uses the Pelli-Robson standard for wide-range desktop diagnostic accuracy.
Frequently Asked Questions
Is this a clinical diagnosis?
No. This online test is a screening and calibration utility. While it accurately follows clinical step-progression, it is not a substitute for a professional eye exam by an optometrist or ophthalmologist.
Can a VCS test detect mold?
A VCS test measures neurological visual response. If your contrast sensitivity is reduced below 1.50 Log CS, it may correlate with neurotoxin exposure (mold/biotoxins). Consult a medical professional for a detoxification protocols.
How often should I take the test?
Monitoring your visual threshold monthly is recommended for individuals tracking recovery from environmental illness or managing chronic eye conditions like glaucoma.