Laser in situ keratomileusis was associated with a negative effect on corneal sensation, which was markedly greater than the effect with PRK and was evident for at least 3 months after surgery.

Recovery of corneal sensation had begun 3 months after LASIK and appeared complete after 12 months.

No abstract

Focal spots of conventional x-ray tubes have a "twin-peaked" intensity distribution perpendicular to the axis of the tube. This results in a poorer modulation transfer function (MTF) than would be obtained with a uniform intensity distribution having the same input power rating (kW). It is demonstrated that such an intensity distribution can be obtained by employing a ribbon-shaped filament. Experimental results are presented for both the ribbon filament and a conventional helical coil using a stationary anode. For a 0.3-mm focal spot spatial frequency of 2.0 c/mm, a uniform intensity distribution gave an MTF of about 50%, compared to 20% for a conventional tube at the same kW rating.

A confocal scanning laser ophthalmoscope has been designed using a slit aperture. It employs an acousto-optic deflector for the laser scanning in the direction parallel to the slit. The slit width is effectively >10 times the diameter of the laser beam spot focused at the subject's retina. The slit aperture effectively reduces the stray light due to scatterers within the eye media and the retinal blood vessels are imaged clearly under red light illumination.