3. • A flat disc with alternative black
and white ring concentrically
arranged around a +3.00D
convex viewing lens.
• This convex lens help to observe
the corneal reflection without
accomodation.
• Also help to magnify the image
• Measure around 7mm of
cornea.
4.
5. Clinical Interpretation
• Circular image - Spherical cornea
• Elliptical image - Astigmatism
• Distorted image - Corneal scar or
other irregularities
• Asymmetrical image-Keratoconus
• Crowding of ring - Steep cornea
• Spread out of ring - Flat cornea
