O prisma é um meio transparente, com definido índice de refração (n) delimitado por duas superfícies não paralelas que possuem o poder desviar para a base os raios luz refratado. É usado em instrumentos ópticos como: biomicroscópio, tonômetro aplanação, ceratômetro Javal, sistema Kepler, medir desvios, lentes dióptricas, avaliação forias verticais, paresias capacidades musculares, horizontais, ...

Since the time of Javal, it has been well established that normal reading eye movement patterns have 3 principal components: (1) small saccades that move the eyes from word to word, (2) large saccades that return the eyes to the beginning of the next line, and (3) fixation pauses between each saccade for information processing. We discuss the vision analysis results and show the quantitative re...

1.1 Definition Astigmatism (from the Greek “a” meaning absence and “stigma” meaning point) is a refractive error (ametropia) that occurs when parallel rays of light entering the nonaccommoding eye are not focused on the retina [American Academy of Ophthalmology (AAO), 2007]. Astigmatism occurs when incident light rays do not converge at a single focal point. The cornea of the normal eye has a u...

PURPOSE Partial Coherence Interferometry (PCI) is a fast, noncontact method to calculate lens implant power for cataract surgery. It has been reported as a potentially more accurate method than ultrasound biometry. Prospective study of the refractive outcomes of a consecutive series of patients undergoing phacoemulsification surgery with preoperative biometry by both ultrasound A-scan and PCI. ...

BACKGROUND A new commercially available device (IOLMaster, Zeiss Instruments) provides high resolution non-contact measurements of axial length (using partial coherent interferometry), anterior chamber depth, and corneal radius (using image analysis). The study evaluates the validity and repeatability of these measurements and compares the findings with those obtained from instrumentation curre...

Acceptance for publication May’ 2011 .................................. Purpose: To compare surgically induced astigmatism between injector and forceps delivery system for intraocular lens implantation in phacoemulsification. Methods: This Quasi experimental study was carried out in Ophthalmology Department, Shaikh Zayed Hospital, Lahore. One hundred consecutive cataract patients were operated ...

Background: A new commercially available device (IOLMaster, Zeiss Instruments) provides high resolution non-contact measurements of axial length (using partial coherent interferometry), anterior chamber depth, and corneal radius (using image analysis). The study evaluates the validity and repeatability of these measurements and compares the findings with those obtained from instrumentation curr...