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 ...

Conical-scam implementations for three antenna types are discussed in terms of the beam nuiatioa method, reference signal generation and angle error demodulation Various applications for these antennas including their use in teaching are discussed. Inder Terms-..eoaical-sean, millimetre wave, antenna I. IN'RODUCiTON Tracking radars require a mechanism to determine the offset of a target from th...

Purpose: To determine whether the changes in the ocular alignment following general anesthesia, maintained with two different inhalational anesthetic agents, sevoflurane and desflurane, can be used as a predictor for surgical outcomes in children with esotropia. Methods: The authors obtained digital photographs of 42 children with esotropia; 21 patients underwent strabismus surgery with general...

Thirty-four female subjects from low socioeconomic group were selected. All were aged between 20 and 35. The study was conducted at physiology research laboratory, Thanjavur Medical College, Thanjavur, from April 2014 to May 2015. A detailed history and thorough clinical and ophthalmic examination was done to rule out any other medical problem besides anemia. Subjects with a history of acute he...

Neuro-otological and posturography findings in 15 patients with visually induced vertiginous symptoms (visual vertigo) are reported. Thirteen patients were considered to have a peripheral vestibular disorder; seven had abnormal caloric or rotational test results. Two patients had CNS disorder--a cerebellar degeneration and a brainstem stroke. Posturography testing showed that five patients show...

ACCORDING to Ciuppers (1958), about 2 per cent. of the population of Germany, France, and Switzerland suffer from unilateral amblyopia; the proportion in Great Britain is likely to be very similar. Though amblyopia resulting from ocular deviation may arise where the fixation is central, the great importance of eccentric fixation in relation to amblyopia is now generally recognized and considera...

In this article, we discuss the potential of radio frequency (RF) lens for ultra-wideband millimeter-wave (mmWave) systems. terms beam squint, compare proposed RF antenna with phase shifter-based array hybrid beamforming. To reduce complexities fully digital beamforming, researchers have come up lens-based The use mmWave systems, however, causes an increase in bandwidth, which gives rise to squ...

As relative bandwidth increases, beam squint, i.e., frequency dependent directivity, limits the wideband performance of phase-shifter steered arrays. This effect is already notable in 5G systems operating at 28 GHz and above with 400/800 MHz bandwidths, especially if broadband cancellation needed between multiple beams. The squinting reduces signal-to-interference-plus-noise-ratio a multibeam s...