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See‐through eyewear displays provide immersive augmented reality experiences by superimposing virtual contents over the view of real‐world scenes. Advancements in AR technologies have led to increasingly complicated design of see‐through eyewear displays (EWDs), presenting challenges to the measurement of their optical parameters and performances. Here we review the challenges and the progress in standardizing such measurements. The latest standard IEC 63145‐22‐20 is discussed, which defines industry benchmarks for evaluating the eyewear displays.

Large screen LED displays are becoming increasingly popular. The human eye has a resolution of 1/60 degree, so at very close viewing the LED chips may be more easily seen because LED screens have a larger pixel pitch than traditional display technologies, unlike OLEDs and LCDs. In large LED displays, the perceived luminance of the pixels is highly dependent on the viewing distance and FOV. The paper examines the perceived pixel luminance of a large screen LED display at different viewing distances and field of views. Additionally, stray light was examined and discussed. The results indicated that the perceived pixel luminance can be significantly different under different viewing distances and FOVs. For future LED display performance evaluation, it would be advantageous to have a measuring device with high resolution that mimics the human eye's angular resolution in perceived pixel luminance.

Eyewear displays have been gradually adopted in entertainment, industrial, and medical applications. The optical performance and image quality of the eyewear displays are required to be precisely evaluated and quantified. This challenges the conventional light measuring devices since the displays are viewed in an immersed environment and at a much closer viewing distance from the display to the eye. In eyewear display, measurement within the eye box and the LMD to mimic the eyeball movement is the first step to ensure an accurate measurement. This paper explained the difference of eyeball location in LMD measurement. The comparison between the eye pupil center and eyeball rotation center which are currently included in the IEC 63145 series standards is discussed. We experimented with the setups in the measurement system and set eye rotation at the pupil and at the eyeball center for contrast ratio and Michelson contrast. The experimental results were discussed to understand the differences between eye pupil center rotation and eyeball center rotation.

Aim:To identify and characterize new mycobacterium pyrazinamide (PZA) resistance genes in addition to pncA, rpsAand panD. Materials & methods:To screen a Tn7 M. smegmatismc2155 transposon library using 50 μM PZA and a PZA hypersensitive mutant (M492) was obtained. MIC was further used to confirm the hypersensitivity of M492 mutant by culturing the mutant in Middlebrook 7H9 liquid medium at 37°C. Results:msmeg_3314is the gene underlying the hypersensitive phenotype of mutant M492. The observed resistance to PZA and fluoroquinolones involved the alteration of Mycobacteriumcell wall permeability and the dissipation of the proton motive force. NAD+/NADH dysregulation and attenuated glyoxylate shunt might underlie the declined scavenging capacity of reactive oxygen species in the msmeg_3314-deficient mutants. Conclusion:msmeg_ 3314is a novel gene involved in pyrazinamide resistance and might be a new candidate for drugs target.

Augmented Reality (AR) has become a hot topic. It seems AR is finally becoming ready for the generals: Public securities have been using AR glasses to assist their public patrol activities, the museum offers the AR glasses to enhance the visitor experience, the oil evaporation workers wear AR headset to help their evaporation operation, etc. However, the one component that is probably most limiting today's popularization is the display's image quality. This paper addressed the image quality of see‐through real scene for AR glasses. Michelson contrast or namely luminance modulation, is measured to evaluate the quality of an see‐through optics. In this paper, we studied the Michelson contrast at different locations of the optics of AR displays. Two types of AR displays were selected for the evaluation and measurement. This paper discussed the two favorable AR type technologies: waveguide and combiner (prism‐combiner).

The HUD (Head‐Up Display) is an optical display system that is commonly used in aircraft as a flight aid to project aircraft flight information onto the display screen (often a type of transparent flat lens) directly in front of the pilot's field of view. This allows the pilot to maintain a level view while taking into account instrument parameters and external visual references in the same field of view. HUDs allow pilots to see crucial navigation, flying, and energy management data on a screen at eye level without having to glance down at their instruments or take their eyes off the outside world. It has been demonstrated that HUDs lessen the pilot workload, improve situational awareness, and decrease accidents. Thus, it is crucial to characterize optical performance and image quality accurately and precisely for aircraft HUDs. In this paper, we reviewed the parameters of optical performance and image quality for aviation‐type HUDs applied under high ambient light levels.