Corneal topography, also known as photokeratoscopy or videokeratography, is a diagnostic imaging technique that uses a scanning device and specialized software to measure the shape, size, thickness, and curvature of the cornea. It is entirely non-invasive, painless, and brief.
After the test is complete, the software digitizes the measurements into three-dimensional maps of the cornea that look similar to heat maps. These demonstrate the information obtained from the scan so that your optometrist can gauge several things like corneal astigmatism and irregularities, as well as fit contact lenses and plan for surgeries like laser vision correction.
The reason measurements of the cornea are so important is because they are responsible for approximately 70% of each eye’s focusing (refractive) power. Corneal irregularities are the cause of many different vision problems, but with standard vision tests, these irregularities can go completely unseen.