Paper
28 September 2016 Corneal topography with conical null-screen for non-symmetric aspheric corneas
Author Affiliations +
Abstract
In this work, we will present some improvements to the conical null-screen based corneal topographer, for testing aspheric surfaces without rotational symmetry. We present the formulae to design the conical null-screen in such a way that the image on the CCD is a perfect array of spots; departures from this geometry are due to deformation or misalignment of the surface. Additionally, we will explain how to improve the algorithms to find the normals of corneal surface. Finally, we will evaluate the topography of a spherical surface.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Victor de Emanuel Armengol-Cruz, Arturo I. Osorio-Infante, Manuel Campos-García, Cesar Cossio-Guerrero, and José Rufino Díaz-Uribe "Corneal topography with conical null-screen for non-symmetric aspheric corneas", Proc. SPIE 9947, Current Developments in Lens Design and Optical Engineering XVII, 994714 (28 September 2016); https://doi.org/10.1117/12.2237372
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Charge-coupled devices

Cornea

Spherical lenses

Aspheric lenses

CCD image sensors

Ray tracing

Natural surfaces

RELATED CONTENT

Accuracy of the optical testing of a fast aspheric concave...
Proceedings of SPIE (November 18 2013)
New null screen design for corneal topography
Proceedings of SPIE (October 25 2011)
Dynamic point shifting in null screen videokeratometry
Proceedings of SPIE (November 02 2011)

Back to Top