These devices not currently US FDA approved † Miller PCRI Nomogram: for symmetric 'bow tie' astigmatism on corneal topography, paired incisions are made in the steep axis, just inside the limbus.

Detecting Irregular Astigmatism or Other Abnormalities. Corneal topography, especially photokeratoscope view and tangential map, plays a critical role in the detection of corneal irregular ...

People with astigmatism may see more glare around lights than those without the condition. This glare may be particularly noticeable at night and may make it difficult to see and drive at night.