THE QUALITY OF VISION IN THE CTENID SPIDER CUPIENNIUS SALEI

Much is known about the mechanosensory behaviour of the spider Cupiennius Keyserling, but much less about its visual capabilities. In this study the quality of the optical image, the retinal resolution and the fields of view were assessed for each of the four pairs of eyes. The image is of good quality in all eyes. The principal (antero-median) eyes lack a tapetum and have an inter-receptor angle of 2.9°. The three secondary eyes (antero-lateral, postero-median and posterolateral) all have ‘gridiron’ tapeta with receptors arranged in rows. The angular separations (along rows × between rows) are 3.6° × 9.3°, 0.9° × 2.3° and 1.0° × 3.0°, respectively. Although the disposition of eyes on the head is similar to that of pisaurid spiders, all other features of the eyes, including the sizes and shapes of the fields of view, resemble those of lycosid spiders. The peripheral visual system of Cupiennius can thus, in principle, support a similar range of visual behaviour to that of lycosids, which includes prey capture, predator avoidance and courtship.

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Olfactory information saves venom during prey-capture of the hunting spider Cupiennius salei (Araneae: Ctenidae)

Functional Ecology ◽

10.1111/j.1365-2435.2006.01103.x ◽

2006 ◽

Vol 20 (2) ◽

pp. 369-375 ◽

Cited By ~ 22

Author(s):

S. HOSTETTLER ◽

W. NENTWIG

Keyword(s):

Prey Capture ◽

Cupiennius Salei ◽

Olfactory Information ◽

Spider Cupiennius Salei ◽

Hunting Spider

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A Visually Induced Switch in Mode of Locomotion of a Spider

Zeitschrift für Naturforschung C ◽

10.1515/znc-1997-1-221 ◽

1997 ◽

Vol 52 (1-2) ◽

pp. 124-128 ◽

Cited By ~ 9

Author(s):

Axel Schmid

Keyword(s):

Behavioral Change ◽

Prey Capture ◽

Complete Darkness ◽

Cupiennius Salei ◽

Locomotion Compensator ◽

Visual Inputs ◽

Sensitivity Range ◽

Locomotion Pattern ◽

Substrate Vibrations ◽

Spider Cupiennius Salei

Abstract The spider Cupiennius salei Keys. (Araneae, Ctenidae) is a nocturnal hunter living on monocotyledones. It does not build webs for prey capture. During the day it remains in its retreat and during dusk it begins to hunt for prey or to search for mates. C. salei is well equipped with mechanosensory systems to detect air- or substrate- borne vibrations elicited by prey or predators. If none of them produce either air movements or substrate vibrations, and the light intensity is below the threshold (0.1 lx), the animal is virtually " blind" . There fore a hypothetical, additional sensory input should exist, which is used only in complete darkness. The animal was tested on a locomotion compensator were it performs constant walks towards a visual target. Three different light intensities were used (bright 200 lx, dim 0.1 lx, and dark at 950 nm, which is outside the spectral sensitivity range of the animal). At bright and dim illumination the animal walked in the alternating tetrapod gait towards the target. In complete " darkness" the walk was no longer directed and the animal changed its gait and continued walking on only six legs using the first pair as guide-sticks. If the first pair is missing, the second cannot replace this function. This shows a twofold use of the first pair o f legs as ordinary walking legs and as guide-sticks or " antennae" . Therefore one can assume that visual input causes a behavioral change, which can not be explained by a fixed locomotion pattern but by adaptive changes caused by visual inputs.

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Quantity and quality of venom released by a spider (Cupiennius salei, Ctenidae)

Toxicon ◽

10.1016/0041-0101(95)00066-u ◽

1995 ◽

Vol 33 (10) ◽

pp. 1347-1357 ◽

Cited By ~ 50

Author(s):

Jean-Luc Boevé ◽

Lucia Kuhn-Nentwig ◽

Sabine Keller ◽

Wolfgang Nentwig

Keyword(s):

Cupiennius Salei ◽

Spider Cupiennius Salei

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Different functions of different eye types in the spider Cupiennius salei.

Journal of Experimental Biology ◽

10.1242/jeb.201.2.221 ◽

1998 ◽

Vol 201 (2) ◽

pp. 221-225 ◽

Cited By ~ 8

Author(s):

A Schmid

Keyword(s):

Visual Information ◽

Mating Behaviour ◽

Visual Fields ◽

Cupiennius Salei ◽

Posterior Median ◽

Simultaneous Choice ◽

Target Detecting ◽

Spider Cupiennius Salei ◽

Median Eyes ◽

Anterior Median

The Central American hunting spider Cupiennius salei Keys relies mainly on its mechanosensory systems during prey-catching and mating behaviour. The behavioural relevance of its eight eyes has not been studied before, although their optics and sensitivity suggest highly developed visual capabilities. The visual system was examined in a twofold simultaneous-choice experiment. Two targets were presented at a distance of 2 m from the animals, and their walking paths towards the targets were monitored. Spiders showed no preference when choosing between two identical targets, but when choosing between two different targets they strongly preferred a vertical bar to a sloping bar or a V-shaped target. By covering all eyes except the anterior median or posterior median eyes, it could be shown that the spiders were able to detect the targets using any of the eyes. Discrimination between different targets was only possible with the anterior median eyes uncovered, although the visual fields of the anterior median and posterior median eyes overlap completely. It seems most likely that the animals separate visual information in the periphery and therefore that the eyes have different functions. The posterior median eyes support a target-detecting mechanism and the anterior median eyes a target-discrimination mechanism.

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The visualization and assessment of the anterior surface of the cornea using video keratotopography

The Eye ◽

10.33791/2222-4408-2020-2-36-43 ◽

2020 ◽

Vol 22 (130) ◽

pp. 36-43

Author(s):

Gulnara Andrienko

Keyword(s):

Contact Lenses ◽

Corneal Topography ◽

Topographic Maps ◽

Specific Situation ◽

Main Method ◽

Pathological Conditions ◽

Quality Of Vision ◽

Corneal Shape ◽

Color Map

Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.

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Evaluation of Quality of Vision and Spectacle Independence With the AcrySof® Panoptix® Intraocular Lens

Case Medical Research ◽

10.31525/ct1-nct04124952 ◽

2019 ◽

Author(s):

Keyword(s):

Intraocular Lens ◽

Quality Of Vision

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Photo demonstration of quality of vision with intact posterior capsule

American Intra-Ocular Implant Society Journal ◽

10.1016/s0146-2776(85)80071-9 ◽

1985 ◽

Vol 11 (4) ◽

pp. 393-395 ◽

Cited By ~ 1

Author(s):

John J. Alpar ◽

James J. Spurlock

Keyword(s):

Posterior Capsule ◽

Quality Of Vision

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Objective and subjective evaluation of trifocal diffractive intraocular Lens after cataract extraction with phacoemulsification: a prospective clinical study

BMC Ophthalmology ◽

10.1186/s12886-021-01937-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ahmed A. Zein El-Dein ◽

Ahmed Elmassry ◽

Hazem M. El-Hennawi ◽

Ehab F. Mossallam

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Intraocular Lens ◽

Subjective Evaluation ◽

Cataract Extraction ◽

Prospective Clinical Study ◽

Gradual Change ◽

Quality Of Vision ◽

Defocus Curve

Abstract Background This study aimed to assess visual outcomes, quality of vision and patients’ satisfaction of a trifocal diffractive intraocular lens after cataract surgery with phacoemulsification. Results The study included 36 eyes that underwent implantation of trifocal diffractive intraocular lens (IOL). The residual mean postoperative spherical equivalent was − 0.40 ± 0.29 diopters. Mean Uncorrected distance visual acuity was 0.80 ± 0.16 decimal (snellen equivalent 25 ft) while mean Uncorrected intermediate visual acuity was 0.82 ± 0.31 decimal (snellen equivalent 25 ft) and mean Uncorrected near visual acuity (UCNVA) was 0.87 ± 0.20 decimal (snellen equivalent 23 ft). In defocus curve, there was infinitesimal gradual change between the three foci. Contrast sensitivity was just below the inferior limit of normal. Conclusion Trifocal diffractive IOL created a true intermediate focus proved by VA and defocus curve and better quality of vision assessed by contrast sensitivity and high order aberration. Moreover, it was safe and effective for correcting distance and near vision in these patients. Most of the patients were very satisfied and achieved spectacle independence. Trial registration Registration number and date: NCT04465279 on July 10, 2020.

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