[Artificial lenses to match the iris].
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Adolescent↗
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Results for “Eye Color”
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Color defect and color theory; studies of normal and colorblind persons, including a subject color-blind in one eye but not in the other.
It is important to find answers to two questions concerning the visual discriminations of dichromatic persons, especially deuteranopes: (i) Do such persons show a loss of sensitivity to various wavelengths of the spectrum as compared with normal subjects? (ii) What colors do they see? A number of experiments were performed on the first question. First, luminosity curves were determined on three groups of subjects, consisting respectively of five protanopes, six deuteranopes, and seven normal individuals. As compared with normal subjects, protanopes show a loss of luminosity in the red, whereas deuteranopes show a loss in the blue-to-green region of the spectrum (See 10). Second, we examined the luminosity curves of a subject whose right eye is classifiable (on the basis of color-mixture determinations) as normal and whose left eye is classifiable as dichromatic. (The hue discrimination curve for her dichromatic eye seemed comparable to the curve of the usual deuteranope except in the violet, where it manifested relatively good discrimination.) The luminosity function for this subject's dichromatic eye, determined by data on threshold and flicker, exhibits the same type of luminosity loss in the blue and green regions of the spectrum as was shown by our group of six deuteranopes. Only unilaterally dichromatic subjects can tell us how colors seen by a dichromatic eye appear to a normal eye. In the color-blind eye, our unilaterally dichromatic subject sees wavelengths below and above her neutral ("grey") point (which occurs at 502 mmicro) as, respectively, a blue equivalent to about 470 mmicro and a yellow equivalent to about 570 mmicro in her normal eye. The results on (i) luminosity loss and (ii) the seeing of wavelengths above 502 mmicro as yellow are considered theoretically. The seeing of yellow by deuteranopes and protanopes may be accounted for by an idea based on Leber-Fick transmation theory. It is proposed that the characteristic sensitivities of the red and green receptors become similar while no change takes place in their central brain connections. Losses may be introduced into the transformed sensitivity curves to indicate appropriate degrees of luminosity deficit for deuteranopes and protanopes.
Color↗
Ocular manifestations of hypercupremia associated with multiple myeloma.
Extensive copper infiltration of Descemet membrane of the central cornea and of the anterior and posterior surfaces of the lens is associated with marked hypercupremia related to an abnormal immunoglobulin. Observation of this spectrum of ophthalmic changes in an apparently well middle-aged woman heralded the diagnosis of a unique variety of multiple myeloma.
Adult↗
Isolation and characterization of the prune locus of Drosophila melanogaster.
The complementary lethal interaction between the prune (pn) and Killer of prune loci of Drosophila melanogaster is an unusual and highly specific phenomenon. A lesion in pn results in a brownish-purple color of the compound eyes, while the conditional dominant Killer of prune mutation exhibits no phenotype by itself. However, a hemizygous or homozygous pn mutant carrying a copy of the Killer of prune gene dies during the late second to third instar stage of larval development. As a step toward understanding the molecular nature of this lethality and the role of pn in pigment biosynthesis, we have cloned the pn locus by using a transposon tag in the P element-induced allele, pn38. In addition, seven independent revertant lines were generated by the remobilization of transposons in pn38. The pn gene is located in a region that is transcriptionally active, and the isolated cDNAs that correspond to this area fall into three transcription units: I, II and III. Southern analysis shows that the restriction fragment length polymorphisms in five pn alleles are localized within a 1.2-kilobase genomic fragment, of which only transcription unit II is a part. The cDNA of this unit recognizes 1.65- and 1.8-kilobase messages in wild-type Drosophila adult head and body tissues that are absent or extremely reduced in pn mutants. Taken together, the results suggest that transcription unit II defines a part of the pn locus and its cDNA encodes a putative structural gene of pn.
Animals↗
Pharmacokinetics of topically applied cyclopentolate HCl and tropicamide.
The time course of accommodative loss after the topical application of 0.5% and 1.0% concentrations of cyclopentolate HCl and tropicamide was measured over a 20-min interval in 50 age- and sex-matched subjects between 20 and 30 years of age. Computer-assisted measures of residual accommodation provided detailed data on the temporal aspects of the cycloplegia induced by these commonly utilized drugs when used alone or with the topical anesthetic proparacaine HCl. The pattern of recovery of ocular accommodation from cycloplegia was also measured over a 5-h period, starting 2 h after drug application. The results show that latency, depth of cycloplegia, and rate of accommodative loss are regulated to drug type and concentration, and are influenced by the iris coloration of the test eye. The rate of onset of cycloplegia was not accelerated in blue or brown irides by the preadministration of proparacaine. Regardless of iris pigmentation, recovery from tropicamide cycloplegia was much faster than recovery from cyclopentolate cycloplegia. In contrast, the depth of cyclopentolate cycloplegia present in brown irides during the recovery phase was much greater than in blue irides. Mechanisms to explain these observations are proposed and clinical implications of these findings are presented.
Accommodation, Ocular↗
[UV light sensitivity of the skin--possibilities and limits of clinical diagnosis].
Our study on 58 test persons showed that the sensitivity of human skin to UV light is independent of the color of skin, hair, eyes or the pigmentation of the mamillae. Therefore, the sensitivity to UV light must be ascertained by subtle phototesting. By means of the new UV phototesting set SBA-LT-400, Saalmann Co., 4900 Herford/West Germany, we determined the minimal erythema doses (MED) of UV-B and UV-A as basic, reproducible parameters regarding Central European people. 7 and 24 hours after radiation, MED showed mean values of 0.032 and 0.037 Joule/cm2, resp., for UV-B, whereas 24.1 and 25.6 Joule/cm2 were measured for UV-A. The pigmentation responses to UV radiation of human skin described in the literature can be reproduced in Mediterranean skin types only.
Adolescent↗
Traumatically acquired color vision defect.
A 24-year-old man acquired a color vision defect shortly after an accident in which he struck the back of his head. Results of the Farnsworth-Munsell 100-hue test showed that the patient had poor color discrimination in both eyes. His color matches on the Nagel anomaloscope suggested a red/green disturbance. Results from increment threshold testing demonstrated on absence of the blue mechanism. Results of field sensitivity measurements confirmed that foveal vision was mediated by the red or green mechanism. This case showed both similarities and differences to previously reported cases of acquired color vision defects secondary to cortical trauma.
Accidents, Traffic↗
Color Doppler imaging of the eye and orbit. A synopsis of a 400 case experience.
Color Doppler imaging (CDI) is a recent advance in ultrasonography that allows simultaneous two-dimensional imaging of structure and blood flow. Doppler information is superimposed in color over a conventional gray-scale ultrasound image. Using this technique we have examined 400 eyes. The central retinal artery, posterior ciliary arteries, ophthalmic artery, the central retinal vein and the vortex veins could be located in all normal eyes. Using the color image as a guide, Doppler spectral analysis is used for quantitative assessment of blood flow velocity in these vessels. We also studied patients with intraocular tumors, arterial and venous retinal occlusions, orbital vascular anomalies and tumors. Color Doppler imaging is a new and promising modality for the study of ocular and orbital hemodynamics.
Blood Flow Velocity↗
Nonlinearities in color coding: compensating color appearance for the eye's spectral sensitivity.
Most wavelengths change hue when mixed with white light. These changes, known as the Abney effect, have been extensively studied to characterize nonlinearities in the neural coding of color, but their potential function remains obscure. We measured the Abney effect in a new way--by varying the bandwidth of the spectrum rather than mixing with white--and this leads to a new interpretation of the role of nonlinear responses in color appearance. Because of the eye's limited spectral sensitivity, increasing the bandwidth of a spectrum changes the relative responses in the three classes of cone receptor and thus would change hue if the percept were tied to a fixed cone ratio. However, we found that hue is largely independent of bandwidth and thus constant for a constant peak wavelength for stimuli with Gaussian spectra. This suggests that color appearance is compensated for the eye's spectral filtering, and that this compensation embodies specific perceptual inferences about how natural spectra vary. When a wavelength is instead diluted with white light--which does not bias the cone ratios--then the same compensation predicts changes in hue because the "right" response is made to the "wrong" stimulus. This model generates constant hue loci that are qualitatively consistent with measures of the Abney effect and provides a novel functional account of such effects in color appearance, in which postreceptoral responses are adjusted so that constant hue percepts are tied to consistent physical properties of the environment rather than consistent physiological properties such as the cone ratios.
Adaptation, Physiological↗
Color Doppler ultrasound measurements after topical and retrobulbar epinephrine in primate eyes.
PURPOSE: To determine the effects of topical epinephrine and retrobulbar anesthesia containing lidocaine with epinephrine on retrobulbar hemodynamic measurements in the primate eye, using color Doppler ultrasound. METHODS: Color Doppler ultrasound measurements were performed at baseline and 90 minutes after masked administration of topical 2% epinephrine or balanced salt solution to six cynomolgus monkeys. Measurements were also performed at baseline and 30 minutes after retrobulbar injection of 2% lidocaine, with or without 1:200,000 epinephrine. RESULTS: After topical epinephrine, color Doppler ultrasound measurements were not significantly different compared with baseline measurements in the central retinal artery, posterior ciliary arteries, and superior ophthalmic vein. There were decreased systolic and diastolic velocities in the ophthalmic artery (P < 0.03 and P < 0.02, respectively) after topical epinephrine; however, Pourcelot's ratio (resistive index) was not significantly different compared with that at baseline. In contrast, there were marked changes in the retrobulbar arterial circulation after retrobulbar injection of lidocaine with epinephrine. The systolic and diastolic velocities were decreased significantly in the central retinal artery (P < 0.02 and P < 0.01, respectively), temporal posterior ciliary artery (P < 0.05 and P < 0.03, respectively), and nasal posterior ciliary artery (P < 0.03 and P < 0.02, respectively). Pourcelot's ratio was significantly increased in the central retinal artery (P < 0.01), temporal posterior ciliary artery (P < 0.02), and nasal posterior ciliary artery (P < 0.02) after retrobulbar injection of lidocaine with epinephrine. CONCLUSIONS: These results indicate that one drop of topical epinephrine has little or no effect on the retrobulbar circulation, whereas retrobulbar injection of anesthetic solution containing lidocaine with epinephrine significantly alters retrobulbar hemodynamics in the monkey eye.
Administration, Topical↗
[A study of para-foveal color vision in normal-tension and primary open angle glaucoma eyes].
A perimetric color vision test developed by Iijima et al. for evaluating parafoveal color vision provides information regarding local retinal function which can not be evaluated by other color vision tests. Using this method, we investigated para-foveal color sensitivity in normal-tension glaucoma (NTG) and primary open angle glaucoma (POAG) eyes whose glaucomatous visual field change determined with the central 30-2 program of the Humphrey visual field analyzer was confined to either the upper or the lower hemifield. The examined eyes had no abnormalities in ocular media with best corrected visual acuity of 1.0 or higher, and age, refraction, mean deviation, and extent of visual field loss were matched between NTG and POAG eyes. In the para-foveal area of the spared hemifield, acquired blue-yellow dyschromatopsia was detected in 52.3% of the POAG eyes and in 11.3% of the NTG eyes (p < 0.02, chi 2-test), and in damaged hemifield, it was found in 76.1% of the POAG eyes and 80.7% of the NTG eyes. We suggest that visual function is more diffusely damaged in POAG than in NTG and that the perimetric color vision test is useful for detecting glaucomatous damage which cannot be detected with conventional light threshold measurements.
Adult↗
DIRECT OBSERVATION OF THE COVERED EYE USING GRADED COMPLEMENTARY COLOR FILTERS.
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Equipment and Supplies↗
Color Doppler imaging of the eye and orbit.
1. The use of color doppler imaging (CDI) in ophthalmology is a new and exciting area in vascular imaging. The physiologic information obtained and the anatomy evaluated has been inaccessible by any other noninvasive or invasive technique. 2. Although CDI for ophthalmic use does not, as of this time, have FDA approval, clinical trials have begun. 3. It is our expectation that CDI will be an accurate, reproducible, noninvasive method to assist ophthalmologists in the diagnosis and treatment of patients with orbital and ocular vascular disease.
Eye↗
Color Doppler imaging of the eye: normal ranges, reproducibility, and observer variation.
Color Doppler ultrasonography has numerous potential applications in the diagnosis and monitoring of many ocular disease processes. One of its advantages over other investigative and diagnostic tests is its safety and repeatability. To be able to fully assess this technique it is important to have good control data and to know the reproducibility of the technique for each of the retrobulbar vessels. Color Doppler ultrasonography was performed on 80 volunteers, and normal ranges of blood velocity were calculated for the ophthalmic artery and for the central retinal artery and vein. Reduction in the peak systolic and end diastolic velocities in the ophthalmic artery and an increase in resistive index in the central retinal artery and vein were noted with advancing age. With regard to reproducibility of the retrobulbar vessels, 15 healthy persons were chosen at random and intra- and interobserver studies performed. The most reliable and reproducible vessels were the ophthalmic artery and central retinal artery and vein. Greater variation was noted in the posterior ciliary vessels, whereas the superior ophthalmic and vortex veins were unreliable in both detection and velocity measurement. The results provide normal ranges for future studies and demonstrate that reproducible results can be obtained for the orbital vasculature using color Doppler imaging.
Adult↗
Ocular and testicular abnormalities in alopecia areata.
Ocular abnormalities similar to those usually found in patients with vitiligo occurred in nine patients with alopecia areata and one patient with poliosis. Exophthalmos, iris color change, discrete depigmentation, and, frequently, associated pigment hyperplasia of the choroid and retinal epithelium were found in the ten patients. Four patients had had a bilateral iris color change from dark brown to blue-green. Hypogonadism, thyroid disease, and poliosis may frequently be associated with pigmentary disturbances of the eye, as well as hair loss. Testicular dysfunction with oligospermatism to aspermatism, hypoandrogyny, hyperretractable testes, and epididymal cyst is reported. Two patients had unilateral and one patient had bilateral testicular atrophy.
Adolescent↗
Sinusoidal flicker characteristics of the color-sensitive mechanisms of the eye.
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Color Perception↗
Photographic monitoring of pathology of the anterior segment of the eye.
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Color↗
Color naming, lens aging, and grue: what the optics of the aging eye can teach us about color language.
Many languages without separate terms for green and blue are or were spoken in locations receiving above-average exposure to ultraviolet-B (UV-B) radiation. It has been proposed that this correlation is caused by premature lens aging. This conclusion was supported by an experiment in which younger observers used the term "blue" less often when they described simulated paint chips filtered through the equivalent of an older observer's lens-removing much short-wavelength light-than when they described the unfiltered versions of the same paint chips. Some stimuli that were called "blue" without simulated aging were called "green" when filtered. However, in the experiment reported here, we found that the proportion of "blue" color-name responses did not differ between younger subjects and older observers with known ocular media optical densities. Color naming for stimuli that were nominally green, blue-green, or blue was virtually identical for older and younger observers who viewed the same (unfiltered) stimuli. Our results are inconsistent with the lens-brunescence hypothesis.
Adolescent↗