Night vision

About: Night vision is a research topic. Over the lifetime, 6004 publications have been published within this topic receiving 67372 citations.

Structural role of the T94I rhodopsin mutation in congenital stationary night blindness.

Abstract: Congenital stationary night blindness (CSNB) is an inherited and non-progressive retinal dysfunction. Here, we present the crystal structure of CSNB-causing T94I2.61 rhodopsin in the active conformation at 2.3 A resolution. The introduced hydrophobic side chain prolongs the lifetime of the G protein activating metarhodopsin-II state by establishing a direct van der Waals contact with K2967.43, the site of retinal attachment. This is in stark contrast to the light-activated state of the CSNB-causing G90D2.57 mutation, where the charged mutation forms a salt bridge with K2967.43 To find the common denominator between these two functional modifications, we combined our structural data with a kinetic biochemical analysis and molecular dynamics simulations. Our results indicate that both the charged G90D2.57 and the hydrophobic T94I2.61 mutation alter the dark state by weakening the interaction between the Schiff base (SB) and its counterion E1133.28 We propose that this interference with the tight regulation of the dim light photoreceptor rhodopsin increases background noise in the visual system and causes the loss of night vision characteristic for CSNB patients.

Method and apparatus of treatment of symptoms of the Irlen syndrom

Abstract: Specially tinted lenses will provide substantial benefits to patients with various forms of visual disturbance caused by a recently identified functional disorder called the Irlen Syndrome of scotopic sensitivity, who show over-stimulation of receptor cells in the wavelength band of 425 to 575 nm. Symptomatically, the Irlen Syndrome is characterized by reduced visual resolution, impaired depth perception, impaired peripheral vision, and ocular vertigo. With use of the lenses the patients report improved visual resolution, increased comfort from reduced symptoms of eye strain, increased depth perception and peripheral vision, and reduced symptoms of ocular vertigo. The treatment includes experientially fitting the patient with lenses of an optimal color and transmission density, namely a predetermined attenuation in the 425-575 nm band. It has been determined according to the invention that pink and peach singly or in combination with blue, green, gray, purple, goldenrod, and yellow tints, can be effectively combined to achieve symptomatic relief. The color and density which is optimal for each patient must be determined individually for each patient and optimized as evaluated by pre-testing and post-testing on the Irlen Differential Perception Scale. Tinting and optical density are further optimized in each patient for near vision, far vision, and night vision.

A night vision device for a vehicle

Abstract: In a night vision arrangement for a motor vehicle in which a camera (1) captures an infra-red image of the roadway in front of the vehicle, a video signal generated by the camera is processed by a signal processor (2) so that the field of view of the image displayed by a display unit (3) is selected in accordance with a control signal The control signal is generated by a signal generator (15) which is responsive to one or more parameters of the movement of the vehicle The width of the field of view may be decreased with increasing speed The axial direction of the field of view may be adjusted depending upon the nature of a turning movement of the vehicle

Topography-guided CATz versus conventional LASIK for myopia with the NIDEK EC-5000: A bilateral eye study.

Abstract: PURPOSE To evaluate the difference in visual acuity, subjective night vision glare, and higher order aberrations in eyes with myopia with or without astigmatism operated with topography-guided customized corneal LASIK and conventional LASIK. METHODS This contralateral study includes 46 eyes (23 patients) that underwent topography-guided corneal customized LASIK using the customized aspheric treatment zone (CATz) ablation profile in one eye and conventional LASIK using the NIDEK EC-5000 Advanced Vision Excimer laser system (NAVEX) in the other eye for myopia with or without astigmatism. Patients were masked to which eye underwent topography-guided CATz or conventional LASIK. Postoperative glare and root-mean-square (RMS) values for total higher order aberrations were measured at 1 and 3 months and compared between the two eyes. RESULTS No significant difference was noted in uncorrected visual acuity between the two groups at 1 and 3 months postoperatively. Of all patients, 81% stated glare was higher in conventionally treated eyes than in the CATz-treated eyes at 1 and 3 months postoperatively. The RMS values for total coma (0.2385 vs 0.1522) and spherical aberration (0.2381 vs 0.1058) in conventionally treated and CATz-treated eyes were significantly higher in conventionally treated eyes (P=.029 and P=.004, respectively) at 3-month follow-up. CONCLUSIONS Topography-guided corneal customized LASIK with the CATz profile gave better night vision quality as compared to conventional LASIK with expanded treatment zone. Better night vision quality was associated with less induced spherical aberrations and coma postoperatively in the CATz treatment group.

Image intensity control in overland night vision systems

Abstract: A near-infrared night vision system includes an infrared source that emits a near-infrared beam toward an object. The infrared beam is reflected from the object as a reflected beam. A camera receives the reflected beam and generates an image signal in response to the reflected beam. An image processor receives the image signal, generates a distribution of the intensities, compares the distribution to a threshold, and generates a display signal based on the comparison. A over-laid heads up display receives the display signal, generates a reflected image in response to the display signal, and overlays the reflected image over the actual image of the object.