This PDF file contains the editorial “Editorial: 1994 in Review: Part II” for OE Vol. 34 Issue 03

This PDF file contains the editorial “Guest Editorial: Optical Engineering in Ophthalmology” for OE Vol. 34 Issue 03

The aim of corneal refractive surgery is to modify the anterior surface of the cornea for the correction of myopia, hyperopia, and astigmatism. The air-tear film interface is a powerful refractive surface. Small changes in the curvature can induce large shifts in refractive power. The exquisite nature of laser-tissue interaction with corneal tissue allows successful application of lasers for refractive surgery. Numerous systems have been developed for clinical applications. An overview is provided of the current clinical and research status of laser refractive surgery.

Pulsed ultraviolet laser ablation is being extensively investigated clinically to reshape the optical surface of the eye and correct vision defects. Current knowledge of the laser/tissue interaction and the present state of the clinical evaluation are reviewed. In addition, the principal findings of internal Food and Drug Administration research are described in some detail, including a risk assessment of the laser-induced-fluorescence and measurement of the nonlinear optical properties of cornea during the intense UV irradiation. Finally, a survey is presented of the alternative laser technologies being explored for this ophthalmic application.

The current status of refractive surgical lasers (including excimer and nonexcimer lasers) is reviewed with an emphasis on photorefractive keratectomy (PRK). The correlation of engineering parameters and the clinical requirements with optimal conditions are presented. The fundamentals of corneal reshaping with formulas for ablation profiles and the advantages of the multizone method are discussed. Updated information on the Mini-Excimer PRK laser system, with an emphasis on the scanning delivery device, is presented. PMMA ablation profiles performed by standard diaphragm and scanning modes are compared for surface ablation quality. Scanning mode ablation patterns for myopia, hyperopia, and regular and irregular astigmatism are presented.

An instrument is developed to measure pupil diameter from both eyes in the dark. Each eye is monitored with a small IR video camera and pupil diameters are calculated from the video signal at a rate of 60 Hz. A processing circuit, designed around a video digitizer, a digital logic circuit, and a microcomputer, extracts pupil diameter from each video frame in real time. This circuit also highlights the detected outline of the pupil on a monitored video image of each eye. Diameters are exported to a host computer that displays, graphs, analyzes, and stores them as pupillograms. The host computer controls pupil measurements and can turn on a yellow light emitting diode mounted just above each video camera to excite the pupillary light reflex. We present examples of pupillograms to illustrate how this instrument is used to measure the pupillary light reflex and pupil motility in the dark.

The use of fixed slit and scanning slit confocal microscopes is described and illustrated for 1-D and 2-D confocal imaging of the in vivo cornea. The 1-D z scanning confocal microscope is described and its performance demonstrated with depth scans across the full thickness of the in vivo rabbit cornea. This instrument uses an axial scanning microscope objective to scan through the full thickness of the in vivo cornea. The instrument is optimized for rapid simultaneous z scans of corneal reflectance and fluorescence. The in vivo application described is the contact-lens-induced time dependence of the fluorescence intensity from the reduced pyridine nucleotides NAD(P)H located within the mitochondria of corneal epithelial cells. The depth resolution of this instrument is 6 m with a 100 x microscope objective and 18 μm with a 50 x microscope objective. A second instrument based on a modified specular microscope with an internal focusing lens is described for 2-D noninvasive monitoring of corneal metabolism. Finally, a real-time, scanning slit confocal microscope is described and demonstrated for obtaining 2-D images of the in vivo human cornea. The unique imaging characteristics of this scanning slit in vivo confocal microscope is illustrated with a series of reflected light images of the normal in vivo human cornea. All of these instruments are modifications of previous instrument designs. The intellectual origins of these instruments are described.

We study the birefringence effect of the in vivo cornea by first using sample lenses that produce a polarization pattern similar to that of the in vivo cornea and, second, by performing computer simulations. The stress analysis of the in vivo cornea is discussed.

In the past few years, a new noninvasive optical ranging technique, partial coherence interferometry, has been developed to measure various intraocular distances. A dual-beam version of this method offers high longitudinal resolution by using laser light with high spatial coherence but short coherence length-15 μm (full width at half maximum)-emitted by a special super luminescent diode. This technique is extended to obtain measurements not only parallel to the vision axis but at arbitrary horizontal and vertical angles to it. This is achieved by a new instrument, a fully computer controlled scanning partial coherence interferometer. By tilting the laser beam in horizontal and vertical directions, this scanning partial coherence interferometer measures the distance from the anterior corneal surface to different points of the retina. These results are then plotted to form topographic images containing information about the contour and the thickness profile of different retinal structures, e.g., the retinal thickness and the retinal nerve fiber layer thickness. Provided that there is no other strong reflection nearby, the absolute position of these retinal layers (respective to the cornea as a reference surface) can be determined in vivo with a precision of 5 μm. Furthermore, the intensities of multiple longitudinal scans at different angles between vision axis and measurement direction can be converted into pixel colors and mounted to form a 2-D false color image. These tomograms show the contour and the structure of different retinal layers.

An instrument suitable for fundus pulsation measurements at preselected points of the retina is developed. Fundus pulsations are measured with a laser interferometer using a single-mode laser diode. Part of the laser light is reflected from the front side of the cornea and part of it is reflected from the retina. The interferences produced by the two remitted waves are detected with a linear CCD array. Evaluation of the interferogram yields the time course of the fundus pulsations. This laser interferometer is coupled to a fundus camera. The setup enables real-time inspection of the laser spot on the fundus. Measurements on seven healthy young subjects are presented. Fundus pulsations in the macular region are significantly smaller than those in the optical disk, but significantly larger than those in peripheral regions of the retina. The association between our results and the subretinal vasculature is discussed and possible future applications of our method are presented.

The optical techniques of the scanning laser ophthalmoscope and its practical applications are described. The technical essence of the optics and electronics of this system for better ophthalmic imaging is pointed out together with the historical development. Basic and clinical applications using many characteristics of the instrument are summarized. Current prospects of the optoelectronic ophthalmoscope and those possible with future technology are given.

During the past three years, indocyanine green (ICG) fluorescence angiography has enjoyed an increasing popularity, especially among clinicians who treat age-related macular degeneration. Although the basic methodology for performing ICG angiography was developed and demonstrated in the early 1970s, nearly 20 years passed before the technology became commercialized for widespread clinical use. The developmental evolution of ICG choroidal angiography and its future clinical uses are discussed.

A laser diode was integrated in a fundus camera to provide narrowband IR illumination for indocyanine green angiography. Carefully designed filter characteristics that made the camera efficient are discussed and compared to a typical non-laser-based fundus camera. The performance of the camera integrated into a digital imaging system was assessed optically and clinically. The system proved to be well suited for the diagnosis of choroidal disease, such as neovascularizations that are difficult to diagnose otherwise.

A method is described that provides measurements of blood flow (ChBF) in discrete regions of the choroidal vascular system. It is based on the technique of laser Doppler flowmetry (LDF). A diode laser beam (wavelength = 810 nm, 60 μW at the cornea) is delivered to the eye through a fundus camera. Light scattered by red blood cells in the tissue volume illuminated by the incident laser beam is detected at the fundus image plane of the camera by an optical fiber. Two analysis schemes of the Doppler signal are developed: one uses commercial skin blood flowmeters and the other a NeXTstation (Motorola 68040 based) computer system. Responses of ChBF to various stimuli are in good agreement with previously published findings in animals. LDF is a valid technique for obtaining noninvasive, continuous, and sensitive recordings of ChBF at discrete regions of the cat eye and in the foveal region of the human fundus, without the need to dilate the pupil.

A new real-time measuring system is developed to visualize the blood flow map of the human retina using dynamic laser speckle effects and a hardware logic circuit. The retina is illuminated with a diode laser spot through a retinal camera, and the speckle field at the image plane of the spot is scanned by an area sensor. The output signal is analog-to-digital (A/D) converted and the blur rate of the intensity at each pixel point is evaluated through a hardware logic circuit specially developed for this system. The results are displayed in 2-D color maps successively at a rate of 16 frames/s, which allows the real-time observation of retinal blood flow.

The Scheimpflug photographic techniques developed in the early 1900s were applied to the ophthalmological field as an anterior eye segment documentation system in the late 1960s and the Scheimpflug camera became commercially available for lens research during the 1980s. Based on the studies utilizing this methodology during the past 10 years, the author developed a new type of device with a CCD camera that is able to analyze data at an almost real-time level with an on-lined computer system. The accuracy of data and reproducibility of documented findings were proved to be satisfactory for both basic and clinical studies of animal and human lenses. Recently, application of this methodology has widened to other parts of anterior eye segment documentation or biometry. Three-dimensional expression of lens findings, which has been the final goal of this photographic application, has already been developed and its significance as an examination will be recognized in the ophthalmological field in the very near future.

Using high luminance point-of-light stimuli, Vernier judgments can be made in the presence of markedly degraded retinal imagery. Without coaching, observers perform center-of-gravity assessments of relative locations of degraded point images. We seek to define, presurgery, individuals who will derive the most benefit from advanced cataract removal (a form of triage), and to determine which of two cataractous eyes has the better postsurgical visual prognosis. There are incredible and growing backlogs of patients with severe cataracts (and other dense media opacities) in the developing world, and generally, limited resources are available for provision of health care. Postcataract surgical failure rates for good visual function are often high, and only one eye is operated on in over 95% of indigent patients treated. Prior to initiating advanced studies in the developing world, at Berkeley we conducted preliminary research on Vernier acuity test techniques on normal adult subjects. We sought to determine the number of repeat trials necessary; to compare a two-point and a three-point Vernier display; to determine the shape of the measured response function at large gap separations between test points (required when testing advanced cataract patients); to assess the effect(s) of a broad range of uncorrected refractive errors on outcomes; and to consider means to minimize refraction-based errors. From these and prior data and analyses, we defined a protocol for use in the developing world. Using a newly designed and rugged precision instrument, these tests were repeated on an advanced cataract population at Aravind Eye Hospital in Madural, India. Although we had much prior experience in India, the initial protocol required major revision on site. Necessary changes in test methods and analytical approaches were made, and next stages in this program were planned. And a new and simple gap "visual acuity" (gap "VA") test was added to the protocol, which greatly facilitated the outcome. The presented material is of interest for several reasons: The health care problems addressed are of considerable social and economic importance; it is valuable to compare the initial protocol and instrument defined in Berkeley and the resultant protocol and instrument designs that finally evolved in India; and the difficulties encountered when seeking to adapt what we thought were simple techniques to patient populations and technical personnel in a "small town setting" (ca. 1 million inhabitants in Madurai alone) in rural south India, are worthy of note. We point out that the Aravind Eye Hospital is an ophthalmological exemplar in the developing world.

A double-pass method is applied to determine the retinal image quality of eyes implanted with intraocular lenses (IOLs). The effect of focus on image quality was measured in two groups of patients that had been implanted with either monofocal or multifocal IOLs. The results show that the overall retinal image quality is reduced in eyes with multifocal lenses with respect to that implanted with monofocal IOLs. Although the depth of focus is larger in multifocal lOLs (4 to 5 D) than in the monofocal IOLs (2 to 3 D), some patients implanted with monofocal IOLs have higher image quality than those implanted with multifocal IOLs in a range of about 4 D around the best focus. In eyes implanted with monofocal IOLs, astigmatism plays a major role to reduce the retinal contrast, but also increases the depth of focus. These "in vivo" measurements show that there is considerable variability in image quality among individuals with the same type of monofocal IOLs. The main factors causing this variability seem to be age and astigmatism produced by surgery.

Visual communication, in the form of telephotography and television, for example, can be regarded as efficient only if the amount of information that it conveys about the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. Elsewhere we have addressed the problem of assessing the end-to-end performance of visual communication systems in terms of their efficiency in this sense by integrating the critical limiting factors that constrain image gathering into classical communication theory. We use this approach to assess the electro-optical design of image-gathering devices as a function of the I number and apodization of the objective lens and the aperture size and sampling geometry of the photodetection mechanism. Results show that an image-gathering device that is designed to optimize information capacity performs similarly to the human eye. For both, the performance approaches the maximum possible, in terms of the efficiency with which the acquired information can be transmitted as decorrelated data, and the fidelity, sharpness, and clarity with which fine detail can be restored.

We propose to test the eye using a diffraction pattern that is formed on the retina. Usually, a test pattern is imaged onto the retina for examination. The use of a diffraction pattern may bring new merits that complement conventional imaging techniques.

A technique for measuring oblique astigmatism error of ophthalmic lenses is described. The technique is based on a Mach-Zehnder interferometer, which allows us to simulate the actual conditions of the eye. The effects of the lens power, the pupilary aperture size and the viewing distance in calculating a projected pupil zone on the lens are discussed. The projected pupil size on the lens affects the measurement result of the oblique astigmatism error. Conversion of the interferogram to astigmatism error in diopters is given.

We report the dynamic memory function of a hybrid bistable system with long-delayed feedback. Up to 51-bit binary data written to and read from an electro-optical bistable system pumped by a He-Ne laser have been demonstrated.

A new method to record a color holographic stereogram and its application in the synthesis of a conical holographic stereogram are presented. The method consists in recording three rainbow holograms on each slit hologram component of the holographic stereogram. To obtain the three images reconstructed on the same place, the position of the projection screen is changed when recording the three rainbow holograms. The difference of the projected image's size coming from the movement of the screen is corrected by introducing a cylindrical lens in the projection system. Results of the method, feasibility, and distortion of the image are discussed.

We discuss our experimental measurement and theoretical modeling of flux distributions from light sources used in waveguide illumination systems. We have constructed a computer-controlled goniometric detection system to map the intensity distributions of these light sources. As an example, we measure the intensity distribution of an incandescent light bulb. This light bulb is used in the waveguide illumination system of an automobile dashboard. The intensity distribution of this light bulb is not uniform. We present a model for this intensity distribution based on radiometric principles and the shape of the light bulb filament. This model describes the light bulb's intensity distribution as a function of the filament's projected area as seen from the detector.

Fractional lower order moments (FLOMs) based on the non-Gaussian stable distribution are employed for texture classification and synthesis. The parameters of a 2-D autoregression model are estimated using the fractional lower order moments, and these parameters are used for texture classification. The analysis of FLOMs is useful when the variance of the underlying distribution is not finite and thus when the whole second-order statistics theory fails; hence, parameter estimation using FLOMs gives a more robust model over the existing methods that use autocorrelation function. This stable distribution is used in the synthesis of texture, and the performance of FLOMs and the autocorrelation methods are compared. By extensive simulations it is shown that the FLOM-based feature extraction algorithm outperforms the autocorrelation-based one.

A new motion compensated predictive coding method for an image sequence at a low bit rate is presented. Motion compensation is based on the segmentation of the reconstructed image performed in both encoder and decoder. This will eliminate the need to transmit the region shape information. Also, motion vector prediction is implemented to reduce the overhead for motion information. Motion-compensated prediction errors are transformed using the discrete cosine transform, and the coefficients are quantized and entropy coded as recommended by CCITT. Computer simulation shows that the proposed coding algorithm significantly reduces the block distortion, as conventional block matching algorithms do at very low bit rates (e.g., 0.02 bit/pixel).

Two hybrid optical/digital systems for access control applications in real-time fingerprint identification are presented. Both involve fingerprint acquisition with a prism, optical Fourier transformation by a lens, data reduction using a wedge-ring detector (WRD), and decision making with a digital computer. One, called the coherent system, performs the Fourier transformation on a coherent fingerprint image introduced directly from a prism, and the other, called the incoherent system, acquires an incoherent fingerprint image, performs preprocessing in a digital computer, and incoherent-to-coherent image conversion before coherent processing. Both systems use the total internal reflection obtained in a prism to introduce the fingerprint image. Decision making is performed by a computer on the WRD output, a feature vector of 64 component digital values. In our experiment, discrimination and error-tolerance performance associated with our two access control systems were tested with four different fingerprints. Initial experimental results show that the incoherent system achieves better performance at the expense of additional equipment.

We propose a phase coding technique for signal recovery of distorted images, and we demonstrate our results through computer simulations. In our demonstration we use two forms of distorted images: (1) a misfocused image and (2) a clean image distorted by passage through a thin aberrating medium. Our results show that even though only a portion of the distortion information was used, we can still recover the original image with a low level of additive noise. The proposed technique opens up the possibility of using all the available types of spatial light modulators for these purposes.

We compute the guided modes of a gyrotropic rib waveguide in the semivectorial approximation. The principal component of the magnetic field is expanded into a two-dimensional Fourier series on a rectangular computational window. The expansion coefficients are determined by the Galerkin method, giving rise to a generalized eigenvalue problem with symmetric matrices, typically of rank 300. The method is easy to implement, is reasonably fast, and compares well with the finite-difference or spectral-index method. The quasi-TM mode equation is the condition of stationarity for a bilinear functional. The latter allows one to derive an expression for the differential nonreciprocal phase shift as a first-order perturbation.

This paper reports the performance and test results of a highpower laser diode transmitter (HPLDT). The HPLDT provides a controlled environment to operate semiconductor lasers with power levels exceeding 0.5 W and is scalable to multi-watt output powers. It provides thermal and optical power control and overdrive protection, and is capable of modulating the laser at high data rates (up to i0 pulses/s). In addition, the HPLDT can accommodate a variety of semiconductor lasers and input modulating signal types over a wide bandwidth.

Measurements of modulation transfer function (MTF), particularly for staring imager systems, are affected by the position of the test target with respect to the rows and columns of the detector array. We demonstrate that random transparency targets of known spatial-frequency content allow shift-invariant MTF measurement in the visible, 3- to 5-μm, and 8- to 12-μm bands. Design criteria and verification procedures for the targets are presented.

All possible solutions for a periodic stack of 10 ZnS-ThF₄ bilayers on a Ag substrate that produce 90-deg differential reflection phase shift at 45-deg angle of incidence and 3.39-μm wavelength are determined. The angular and wavelength sensitivity of several of these designs is considered. To increase the reflectance, reduce the diattenuation, and improve the sensitivity of the 20-layer reflection quarterwave retarder (QWR), we also consider quasiperiodic stacks. These designs are obtained by iteration starting from an initial high-reflectance, 10-bilayer, non-QWR, periodic structure and adjusting the thicknesses of the two films of the topmost bilayer to realize the desired 90-deg retardance. Again multiple solutions are obtained for each initial design and their angular and wavelength sensitivity are analyzed. It is found that the best sensitivity corresponds to the lowest and nearly equal optical thicknesses of the two films of the topmost bilayer. Performance comparable to that reported in the literature, obtained for more complicated stacks in which the thicknesses of all 20 films are different, is reported.

A phased array telescope is an array of optical telescopes whose images are coherently combined so as to achieve the resolution of a single but much larger telescope. Phased array telescopes deliver the resolution of very large telescopes without the difficulties and expenses associated with very large optics. To achieve this resolution, a wide field of view (FOV) phased array imaging system must accurately control phase and must superimpose the images from all telescopes to within a fraction of a resolution element over the whole FOV simultaneously. We built a test bed called the Multipurpose Multiple Telescope Testbed (MMTT). It consists of four 20-cm-aperture telescopes phased together with a ± 15-arcmin FOV. It has no mount and is designed for laboratory use only. We present a brief description of the MMTT and then describe performance tests and results. The phasing and image superpositioning accuracy of the array were measured using star tests. Several of the resulting point spread functions were recorded simultaneously at three different field angles to determine the wide FOV performance of this phased array. These images were analyzed and compared to theoretical predictions.

The feasibility of using amorphous silicon photodetectors as receivers in optical interconnection is discussed. The amorphous silicon could be deposited on top of the silicon chip so that the entire chip area could be dedicated to processor and memory circuits. Utilizing the parallelism afforded by fabricating arrays of large numbers of modulators and receivers would provide communication bandwidth far in excess of electronic interconnects even though individual receivers operated at modest speed. A preliminary experiment was carried out to determine important issues such as photosensitivity and interfacing between the amorphous silicon sensor and crystalline silicon circuit. The results show that amorphous silicon photodetectors have high photosensitivity. A bipolar-junction-transistor voltage comparator or CMOS inverter can be used to amplify the photocurrent generated by the detector to the level required by very large scale integration circuits. Systems using amorphous silicon detectors could offer large-bandwidth parallel communication channels for multiprocessors, based entirely on proven, compatible materials and processes.

An architecture is described incorporating the advantages of both digital and optical image processing. This hybrid system for object identification builds on the parallel and instantaneous processing of the optical correlator technology and digital techniques to display and record optical images and filters. A hierarchical computational logic leads to recognition and object identification through three levels of increasing computational complexity. The shape analysis leads to classification by the geometrical parameters, including scale, shape, and rotation for each blob. Filters are stored and indexed by their geometrical descriptors. The optical image processor recognizes objects by performing a correlation operation on computer-stored filters, generated with a priori knowledge.

The realization of a coherent frequency-modulated continuous-wave LIDAR aimed for the accurate measurement of short distances employing a distributed feedback tunable twin-guide laser diode is demonstrated. Theoretical calculations on the ultimate limits in accuracy of distance measurements as determined by the laser phase noise are carried out. A relative accuracy of 8x 10^-5 (8 μm) for a single-shot measurement has been achieved at a distance of 10 cm, which is significantly better than expected from the laser linewidth. The results presented here prove the predictions calculated from theory.

A 3-D range sensor using triangulation collects large files of range data for an object surface. The available range data may be reduced to a more manageable set for surface reconstruction by using multiresolution analysis and wavelet transformation. This reduction of the data file size may be achieved without losing the essential characteristics of the surface by imposing proper requirements on the scaling function of the wavelet transform. These requirements are determined by considering either the type of scanned surface or the reconstruction method used here: a polyhedral surface fitting. Wavelet transformations corresponding to different scaling functions are used to produce reduced data sets from the original one; subsampling is achieved using the Battle-Lemarié linear spline and cubic spline scaling functions and an eight-coefficient Daubechies compactly supported scaling function. A short description of the acquired range data, the application of wavelet transformation to the data, and test results on surface reconstruction are presented.

Complex index-of-refraction values of RP-1 liquid rocket fuel are reported at laser wavelengths of 0.193 μm (ArF excimer), 0.4765 μm (argon ion), 0.488 μm (argon ion), 0.5145 μm (argon ion), 0.532 μm (Nd-YAG, frequency doubled), 0.6328 μm (He-Ne), 1.064 μm (Nd-YAG), and 10.5915 μm (CO₂). The imaginary part of the index of refraction (k) is determined by traditional transmission methods. The real part (n_r) at the specific laser lines is determined using reflectance measurements, critical-angle measurements, Mueller matrix elements, and Michelson interferometric measurements. Reflectance measurements are used to obtain n_r at a wavelength of 0.193 μm. The critical-angle method is used to determine n_r at 0.4765, 0.488, 0.5145, and 0.532 μm: the real part of the refractive index is obtained from Snell's law by measuring the critical angle. The real part of the refractive index at 0.6328 and 1.064 μm is derived from elements of the Mueller matrix, which are obtained using a TMA Technologies scatterometer. A Michelson interferometer is used to obtain phase shifts in a wedge cell, which are then used to calculate n_r at 10.5915 μm. The need for many methods to measure the complex index of refraction is a result of the large changes in k over the wavelengths of interest.

A multiresolution edge detection algorithm for speckle images is proposed. Due to the signal dependence of speckle noise, the vanance of a speckle image depends on the local average intensity; thus an edge detection method independent of the local average intensity is desirable for correct extraction of real, significant changes in an original signal. In the proposed method, each area having different resolution is first classified according to the statistical properties of a speckle image, namely, a discontinuity measure such as the ratio of variance to mean square or the maximum difference between the real and theoretical cumulative density functions. Then the real edges are extracted in a multiresolution environment. Computer simulation with several test images shows that the proposed method significantly reduces false edges in relatively homogeneous areas while detecting fine details properly. Also, simulation results from the conventional edge detection methods for speckle images are compared with those of the proposed method.

A new computational approach for determining the parameters that characterize the locations of trajectories of point targets in a 3-D space is described. The targets of concern are dim, unresolved point targets moving along straight paths across the same field of view. Since the target's signal-to-noise ratio is low and the spatial extent of the target is less than a pixel, one must rely on integration over a target track that spans many image frames. The proposed method estimates these parameters by transforming the entire set of time-sequential images of a constant field of view into the projection space by using a modified Radon transform. Since the 3-D (spatiotemporal) data can be decomposed into 2-D multiple-view representations along arbitrary orientations, the Radon transform enables us to analyze the 3-D problem in terms of its 2-D projections. When this generalization of the Hough transform-based algorithm using the Radon transform is applied to a set of real infrared images, it produces promising estimation results even under noisy conditions. The noise in the images is assumed to be additive white Gaussian.

This PDF file contains the editorial “Book Rvw: Integrated Optoelectronics," edited by Mario Deganais, Robert F. Leheny, and John Crow for OE Vol. 34 Issue 03