purpose : to determine the fusional amplitudes and the frequency of hetrophoria, in our patients methods : in this cross sectional study, 111 adults with mean age of 25.6 years were included. all participants had best corrected visual acuity (bcva) better than 20/25, more than 60 sec of arc stereopsis and had no heterotropia or other significant eye disorders. fusional amplitudes were measured ...

PURPOSE This study was designed to determine the repeatability of fusional vergence ranges measured using the rotary prisms in the phoropter and in free space using the prism bar. The level of agreement between the two methods was also investigated. METHODS In two separate sessions, negative and positive fusional vergence ranges (NFV and PFV, respectively) were measured at distance and near i...

A novel method is proposed for measuring the six degrees-of-freedom (DOF) geometric motion errors of a rotary axis based on polyhedral prism. An error-sensitive unit which consists prism and planar reflector, designed to carry out measurement all DOF errors, including angular positioning error, tilt error around Y axis, X radial along axes, axial Z axis. The mathematical model, installation bet...

JOHANNESBURG IN ophthalmology there are two schools of thought, the physiological and the physical or mechanical school. Thus Williamson-Noble', dealing with my method of treating eyestrain, states: "curiously enough, Stutterheim designates the condition which his exercises are designed to improve as " involuntary convergence," whereas, as you will shortly see, it is the ability to perform the ...

Introduction: Optical coherence tomography (OCT) is a new optical imaging technique that can provide cross-sectional images of biological tissue, highly desirable for imaging diagnosis of superficial lesions [1]. OCT can delineate tissue micro morphology, holding the potential for non-invasive optical biopsy [1, 2]. In recent years, the development of real-time, high-performance, reliable and l...

To meet the demand of high-accuracy, long-range and portable use in large-scale metrology for pose measurement, this paper develops a 6-degree-of-freedom (6-DOF) measurement system based on total station by utilizing its advantages of long range and relative high accuracy. The cooperative target sensor, which is mainly composed of a pinhole prism, an industrial lens, a camera and a biaxial incl...

Initiative: The Tygerberg Children's Hospital and Rotary Telemedicine Project in South Africa links specialists from Tygerberg Hospital to doctors at regional community or "district" hospitals to improve healthcare in rural areas. The initiative has assembled its own telemedicine system using off-the-shelf computer equipment and software that is more affordable than commercial telemedicine syst...