Skip to main content
Hashemi Eye Care - Neuroscience Institute and Research Center

Contrast Sensitivity Testing

A test measuring your ability to distinguish objects from their background, often affected in optic nerve conditions.

2 min read

Contrast sensitivity testing measures how well you can distinguish objects that don't stand out clearly from their background—like seeing a gray car on a foggy day. This can be reduced even when standard visual acuity is normal.

Key Takeaways

  • Measures ability to see low-contrast objects
  • Often abnormal in optic nerve disease
  • May be affected even with good acuity
  • Explains difficulty in dim lighting, fog
  • Quick office test

Why It's Done

  • Detect optic nerve dysfunction not seen on acuity testing
  • Monitor optic neuritis recovery
  • Evaluate MS-related visual problems
  • Assess functional vision more completely
  • Explain visual complaints despite "good" acuity

What It Tests

Standard visual acuity charts use high contrast (black letters on white). But real life has many low-contrast situations:

  • Driving in fog or rain
  • Dim lighting
  • Faces in shadows
  • Gray objects on gray backgrounds

Types of Tests

Pelli-Robson Chart

  • Letters decrease in contrast (fade to gray)
  • Easy to perform
  • Most common clinical test

Contrast Sensitivity Function (CSF)

  • Tests different sizes and contrasts
  • More detailed assessment
  • Research and specialty settings

Low-Contrast Letter Charts

  • Like standard acuity chart but gray letters
  • Sloan low-contrast charts common

What to Expect

  • Similar to regular eye chart reading
  • Letters or patterns at decreasing contrast
  • Each eye tested separately
  • Takes 5-10 minutes

Interpreting Results

Normal

  • Can read low-contrast targets
  • Good real-world vision expected

Reduced

  • Difficulty with low-contrast targets
  • May explain visual complaints
  • Common in optic nerve disease
  • May persist after acuity recovers
Was this article helpful?