Jackson Cross Cylinder

cross cylinder ablation in lasik for high astigmatism

purpose: to evaluate the visual outcomes of cross-cylinder ablation in laser in situ keratomileusis (lasik) for eyes with high astigmatic refractive errors and low spherical component. methods: we prospectively evaluated cross cylinder lasik in patients with high astigmatic refractive error but low spherical component over a period of 2 years. all procedures were performed with the nidek ec-500...

A Possible Fallacy in the Use of the Cross-cylinder.

NEARLY 50 years ago Edward Jackson described the cross-cylinder test for determining, subjectively, the amount of astigmatism present in a patient, and some 14 years later, he described how it could also be used to determine the axis of the astigmatism. It was a long tithe before the value of Jackson's teaching was generally appreciated and as recently as 1931, William Crisp, I in an address to...

Full-View Panoramic Navigation Using Orthogonal Cross Cylinder

Orthogonal Cross Cylinder (OCC) is an object created by intersecting the cylinder of Y-axis and the cylinder of the Z-axis. OCC mapping is a new method for effectively mapping the environment. This method eliminates the singularity effect caused in the environment maps and shows an almost even amount of area for the environment occupied by a single texel. The surrounding environment can also be...

Orthogonal Cross Cylinder Using Segmentation Based Environment Modeling

Orthogonal Cross Cylinder (OCC) mapping and segmentation based modeling methods have been implemented for constructing the image-based navigation system in this paper. The OCC mapping method eliminates the singularity effect caused in the environment maps and shows an almost even amount of area for the environment occupied by a single texel. A full-view image from a fixed point-of-view can be o...

Blanket Cylinder Impression Cylinder Printing Plate Cylinder Moistening Roller