Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

New null screen design for corneal topography

[+] Author Affiliations
Manuel Campos-García, Amilcar Estrada-Molina, Rufino Díaz-Uribe

Univ. Nacional Autónoma de México (Mexico)

Proc. SPIE 8011, 22nd Congress of the International Commission for Optics: Light for the Development of the World, 801124 (October 25, 2011); doi:10.1117/12.903397
Text Size: A A A
From Conference Volume 8011

  • 22nd Congress of the International Commission for Optics: Light for the Development of the World
  • Ramón Rodríguez-Vera; Rufino Díaz-Uribe
  • Puebla, Mexico | August 15, 2011

abstract

In this work we report the design of a null screen for corneal topography. Here we assume that the corneal surface is an ellipsoid with a diameter of 12 mm and a curvature radius of 7.8 mm. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with spots (similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact radial array of circular spots if the surface is perfect. Additionally, we performed a numerical simulation introducing Gaussian random errors in the coordinates of the centroids of the spots on the image plane, and in the coordinates of the sources (spots on the null-screen) in order to obtain the conical null-screen that reduces the error in the evaluation of the topography.

© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation

Manuel Campos-García ; Amilcar Estrada-Molina and Rufino Díaz-Uribe
"New null screen design for corneal topography", Proc. SPIE 8011, 22nd Congress of the International Commission for Optics: Light for the Development of the World, 801124 (October 25, 2011); doi:10.1117/12.903397; http://dx.doi.org/10.1117/12.903397


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement

  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.