OBJECTIVE The purpose of this work is to evaluate the impact of optimization of magnification on performance parameters of the variable resolution X-ray (VRX) CT scanner. METHODS A realistic model based on an actual VRX CT scanner was implemented in the GATE Monte Carlo simulation platform. To evaluate the influence of system magnification, spatial resolution, field-of-view (FOV) and scatter-...

BACKGROUND In the past, practitioners have used distance and/or near visual acuity (VA) to calculate required magnification for low vision aids. Magnification was usually under-estimated when compared with the final magnification prescribed. Recent studies have emphasised the importance of acuity reserve in determining the required magnification for optimum reading rate. Two different approache...

Some recent developments in the area of multi-scale viewing have concerned the creation of such views from magnification factors as input. We present an algorithm in which magnification factors are used directly to control the creation of a multiscale view in a 3D based distortion viewing. Our algorithm relies on the basic geometry of a perspective view volume, the properties of which provide a...

In the past, patients with uniocular cataracts who underwent cataract extraction were not able to tolerate aphakic spectacles due to 30% magnification of visual images thus giving rise to diplopia. The other alternative was to use contact lens which needed motivation. Some could not tolerate contact lens and its magnification of 5% to 7%. These failures eventually led to the idea of intraocular...

We measured linear cortical magnification factors in V1 with fMRI, and we measured visual acuity (Vernier and grating) in the same observers. The cortical representation of both Vernier and grating acuity thresholds in V1 was found to be roughly constant across all eccentricities. We also found a within-observer correlation between cortical magnification and Vernier acuity, further supporting c...