Eyelid closure causes myopia in humans

Humans with unilateral ptosis are more myopic in the closed eye than in the normal eye. The effect seems unrelated to visual loss. In pairs of humans ranked for sleep and myopia, the more myopic tends to sleep the more. We conclude that eyelid closure causes myopia.     

Graph-based inductive reasoning

This article discusses methods of inductive inferences that are methods of visualizations designed in such a way that the “eye” can be employed as a reliable tool for judgment. The term “eye” is used as a stand-in for visual cognition and perceptual processing. In this paper “meaningfulness” has a particular meaning, namely accuracy, which is closeness to truth. Accuracy consists of precision and unbiasedness. Precision is dealt with by statistical methods, but for unbiasedness one needs expert judgment. The common view at the beginning of the twentieth century was to make the most efficient use of this kind of judgment by representing the data in shapes and forms in such a way that the “eye” can function as a reliable judge to reduce bias. The need for judgment of the “eye” is even more necessary when the background conditions of the observations are heterogeneous. Statistical procedures require a certain minimal level of homogeneity, but the “eye” does not. The “eye” is an adequate tool for assessing topological similarities when, due to heterogeneity of the data, metric assessment is not possible. In fact, graphical assessments precedes measurement, or to put it more forcefully, the graphic method is a necessary prerequisite for measurement.     

Role of host-defence peptides in eye diseases

The eye and its associated tissues including the lacrimal system and lids have evolved several defence mechanisms to prevent microbial invasion. Included among this armory are several host-defence peptides. These multifunctional molecules are being studied not only for their endogenous antimicrobial properties but also for their potential therapeutic effects. Here the current knowledge of host-defence peptide expression in the eye will be summarised. The role of these peptides in eye disease will be discussed with the primary focus being on infectious keratitis, inflammatory conditions including dry eye and wound healing. Finally the potential of using host-defence peptides and their mimetics/derivatives for the treatment and prevention of eye diseases is addressed.     

Acetylcholinesterase decrease in the optic lobe after unilateral eye deprivation

Unilateral eye enucleation in a teleost and a turtle results in progressive AChE decrease in the optic lobe controlateral to the extirpated eye. The final difference reaches 15% in teleost and more than 20% in turtle. No drastic differences in localization, but a rearrangement of histochemical pattern, due to the degeneration of retinal fibres, is noticed.     

Acetylcholinesterase decrease in the optic lobe after unilateral eye deprivation

Summary Unilateral eye enucleation in a teleost and a turtle results in progressive AChE decrease in the optic lobe controlateral to the extirpated eye. The final difference reaches 15% in teleost and more than 20% in turtle. No drastic differences in localization, but a rearrangement of histochemical pattern, due to the degeneration of retinal fibres, is noticed.     

基于人眼状态识别的驾驶员疲劳检测方法研究

提出一种基于眼睛状态识别的驾驶员疲劳状态检测的方法。首先通过建立肤色模型分割出人脸区域,再利用搜索连通域的方法实现眼睛区域的定位;然后计算出眼睛区域的垂直积分投影曲线,提取并比较曲线的特征参数,从而识别眼睛的状态;最后以眼睛闭合时间比率为测量标准实现对驾驶员疲劳程度的检测。实验表明,该方法简单、有效、实时性较好,疲劳检测的正确率较高。     

The concept of “character” in Dirichlet’s theorem on primes in an arithmetic progression

In 1837, Dirichlet proved that there are infinitely many primes in any arithmetic progression in which the terms do not all share a common factor. We survey implicit and explicit uses of Dirichlet characters in presentations of Dirichlet’s proof in the nineteenth and early twentieth centuries, with an eye toward understanding some of the pragmatic pressures that shaped the evolution of modern mathematical method.     

3-OH-Kynurenine content and ommochrome formation in the developing compound eye ofEphestia kühniella

Summary The eye color ofEphestia kühniella is primarily determined by the ommochromes xanthommatin and ommin. The pigmentation, an important part of eye differentiation, occurs mainly during the pupal stage. Comparative studies on eye colour mutants indicate that a first step in ommochrome synthesis is the binding of the precursor 3-OH-kynurenine to developing pigment granules. Both xanthommatin and ommin are present from the early beginning of eye differentiation, and exhibit different developmental profiles.     

Testosterone and eye-brain asymmetry for copulation in chickens

Summary Asymmetry of eye function has been demonstrated in the young chicken. Precocious copulation following intramuscular treatment with testosterone can be elicited by presentation of an appropriate stimulus to the left eye, but not to the right eye.     

Die Augenstielbewegungen der Languste (Palinurus vulgaris)

Summary Palinurus vulgaris shows clear compensatory eye stalk movements when turning actively around a vertical axis. Exactly the same eye stalk movements are observed after blinding of the animal (measurement of film pictures). On passive rotation only the intact animal shows compensatory eye stalk movements (= optomotoric reactions); in the blinded lobster such movements are lacking, except when a torsion of the body with respect to the legs is effectuated (stimulation of proprioceptors). It is suggested that the compensatory eye stalk movements of the actively turningPalinurus are no optomotoric reactions, and possibly no sensory reactions at all; but that they are spontaneous acts originating primarily within the central nervous system.     

Somatotopic organization of the eye muscle representation in the semilunar ganglion.

A somatotopic arrangement of the extraocular muscle proprioception has been found in the semilunar ganglion. The cells innervating the proprioceptors of the superior rectus and superior oblique muscles lie more dorsally than those innervating the inferior rectus and inferior oblique. The lateral rectus and the medial rectus are represented in the lateral, respectively in the medial portion of the cellular pool which provides the sensitive innervation of the eye muscles.     

Morphine eye-drops reduce homatropine induced mydriasis in man

Summary In 7 healthy volunteers 4% morphine eye-drops, when administered to one eye, caused a miosis limited to that eye. In 7 other healthy volunteers morphine was administered into one eye after bilateral instillation of 0.5% homatropine opthalmic drops; the eye treated with morphine and homatropine showed a mydriasis less intense than the other eye treated only with homatropine. It is suggested that topical morphine locally affects sympathetic function by inhibiting noradrenaline release into the iris neuromuscular junction.This work was partly supported by the CNR study group Pain Control. The authors wish to thank Dr Tendi of the Pharmacy of St. Maria Nuova Hospital, Florence, for the preparation of the eye-drops.     

Light dependent accumulation of macrophages at the photoreceptor-pigment epithelial interface in the retina of albino mice

Summary In the subretinal space of albino mice, macrophages appear from the time of eye opening and increase in number for 6 months; thereafter they decline with age. Dark rearing retards the accumulation of these cells, and exposure to constant light results in a rapid increase. Observations suggest that macrophages appear as a response to visual cell decay in albino mice and supplement the phagocytic activity of the pigment epithelium.We thank R.K. Hawkins for efficient management of the animal colony, H.G. Jansen for cooperation in the use of electron microscope and Ms Paula van Alphen for help in preparation of the illustrations.     

Somatotopic organization of the eye muscle representation in the semilunar ganglion

Summary A somatotopic arrangement of the extraocular muscle proprioception has been found in the semilunar ganglion. The cells innervating the proprioceptors of the superior rectus and superior oblique muscles lie more dorsally than those innervating the inferior rectus and inferior oblique. The lateral rectus and the medial rectus are represented in the lateral, respectively in the medial portion of the cellular pool which provides the sensitive innervation of the eye muscles.This work was supported by a grant of CNR.     

Neurotrophin-conjugated nanoparticles prevent retina damage induced by oxidative stress

Glaucoma and other optic neuropathies are characterized by a loss of retinal ganglion cells (RGCs), a cell layer located in the posterior eye segment. Several preclinical studies demonstrate that neurotrophins (NTs) prevent RGC loss. However, NTs are rarely investigated in the clinic due to various issues, such as difficulties in reaching the retina, the very short half-life of NTs, and the need for multiple injections. We demonstrate that NTs can be conjugated to magnetic nanoparticles (MNPs), which act as smart drug carriers. This combines the advantages of the self-localization of the drug in the retina and drug protection from fast degradation. We tested the nerve growth factor and brain-derived neurotrophic factor by comparing the neuroprotection of free versus conjugated proteins in a model of RGC loss induced by oxidative stress. Histological data demonstrated that the conjugated proteins totally prevented RGC loss, in sharp contrast to the equivalent dose of free proteins, which had no effect. The overall data suggest that the nanoscale MNP-protein hybrid is an excellent tool in implementing ocular drug delivery strategies for neuroprotection and therapy.     

Influence of oxygen concentration on development ofDrosophila melanogaster

Summary 1st, 2nd, and early 3rd instarDrosophila larvae are extremely sensitive to 100% O₂ or 75% O₂/25% N₂ (at atmospheric pressure) whereas eggs, late 3rd instar larvae, and pupae are relatively insensitive under our exposure conditions. Eclosing flies exposed to an O₂ enriched environment consistently possessed 2 eye abnormalities: dark eye color and altered eye shape.Supported by NSF-URP grant SP1782684 and a Summer Faculty Fellowship to Harry Nickla.     

Choroidal and iris angioarchitecture of the newt: A scanning electron-microscopic study of vascular corrosion casts

The corrosion cast technique provided for the first time an excellent three-dimensional visualization of the vascular pattern of the choroid and iris in the newt eye. The results show the presence of a single arterial afference to the choroidal and iris capillaries: the ophthalmic artery is the origin fo both ciliary arteries and the long posterior ciliary artery. Slightly behind the equatorial circumference of the eyeball the venous drainage consists of a single vessel on the dorsal side and two distinct vessels on the ventral one. It receives blood from both iris and choroid. The surface of the plastic endocasts shows some details of fine luminal structures of the endothelial cells. Shallow depressions may be regarded as imprints of endothelial cell nuclei, and they are distinctly different for arteries and capillaries. The angioarchitecture of the newt eye differs from that of brain in that hairpin-shaped capillary loops are not observed at all.