The Eye
... It is a delicate membrane, which continues posterior and joins to the optic nerve Two special types of light-sensing cells are in the retina; they contain photo pigments, which cause a chemical change when light hits them 1. Cones: used mainly for light vision 2. Are sensitive to color; located in a ...
... It is a delicate membrane, which continues posterior and joins to the optic nerve Two special types of light-sensing cells are in the retina; they contain photo pigments, which cause a chemical change when light hits them 1. Cones: used mainly for light vision 2. Are sensitive to color; located in a ...
ch17 special senses
... dense fibrous tissue that covers all the eyeball, except the most anterior portion, the iris; the sclera gives shape to the eyeball and protects its inner parts. Its posterior surface is pierced by the optic nerve. 2) The cornea is a nonvascular, transparent, fibrous coat through which the iris can ...
... dense fibrous tissue that covers all the eyeball, except the most anterior portion, the iris; the sclera gives shape to the eyeball and protects its inner parts. Its posterior surface is pierced by the optic nerve. 2) The cornea is a nonvascular, transparent, fibrous coat through which the iris can ...
ch17 outline
... a. The fibrous tunic is the outer coat of the eyeball. It can be divided into two regions: the posterior sclera and the anterior cornea. At the junction of the sclera and cornea is an opening known as the scleral venous sinus or canal of Schlemm (Figure 17.7). 1. The sclera, the “white” of the eye, ...
... a. The fibrous tunic is the outer coat of the eyeball. It can be divided into two regions: the posterior sclera and the anterior cornea. At the junction of the sclera and cornea is an opening known as the scleral venous sinus or canal of Schlemm (Figure 17.7). 1. The sclera, the “white” of the eye, ...
CHAPTER - 11 THE HUMAN EYE AND THE COLOURFUL WORLD
... 1a) The human eye :The human eye is the sense organ which helps us to see the colourful world around us. The human eye is like a camera. Its lens system forms an image on a light sensitive screen called retina. The eye ball is almost spherical in shape with a diameter of about 2.3cm. Light enters t ...
... 1a) The human eye :The human eye is the sense organ which helps us to see the colourful world around us. The human eye is like a camera. Its lens system forms an image on a light sensitive screen called retina. The eye ball is almost spherical in shape with a diameter of about 2.3cm. Light enters t ...
Slide 1
... 1a) The human eye :The human eye is the sense organ which helps us to see the colourful world around us. The human eye is like a camera. Its lens system forms an image on a light sensitive screen called retina. The eye ball is almost spherical in shape with a diameter of about 2.3cm. Light enters t ...
... 1a) The human eye :The human eye is the sense organ which helps us to see the colourful world around us. The human eye is like a camera. Its lens system forms an image on a light sensitive screen called retina. The eye ball is almost spherical in shape with a diameter of about 2.3cm. Light enters t ...
The Human Eye and the colourful world
... A delicate membrane having a large number of light-sensitive cells called Rods and cones which respond to the intensity of light and colour of objects respectively. ...
... A delicate membrane having a large number of light-sensitive cells called Rods and cones which respond to the intensity of light and colour of objects respectively. ...
Receptors - Virtual Medical Academy
... Rods about 125 million. The principal light sensitive chemical in the rod is the Rhodesian (visual pigment in the rod cells). ...
... Rods about 125 million. The principal light sensitive chemical in the rod is the Rhodesian (visual pigment in the rod cells). ...
The Eye and Vision
... waves from outside objects. • The convex surface of the lens, and to a lesser extent, the surfaces of the fluids within chambers of the eye then refract the light again. • If eye shape is normal, light waves focus sharply on the retina. • The image that forms on the retina is upside down and reverse ...
... waves from outside objects. • The convex surface of the lens, and to a lesser extent, the surfaces of the fluids within chambers of the eye then refract the light again. • If eye shape is normal, light waves focus sharply on the retina. • The image that forms on the retina is upside down and reverse ...
Lecture notes for Chapter 15
... More numerous, more sensitive to light than cones No color vision or sharp images Numbers greatest at periphery Cones Vision receptors for bright light High-resolution color vision Macula lutea exactly at posterior pole Mostly cones Fovea centralis Tiny pit in center of macula with all cones; best v ...
... More numerous, more sensitive to light than cones No color vision or sharp images Numbers greatest at periphery Cones Vision receptors for bright light High-resolution color vision Macula lutea exactly at posterior pole Mostly cones Fovea centralis Tiny pit in center of macula with all cones; best v ...
Chapter 17
... electrodes translate sounds into electric stimulation of the vestibulocochlear nerve – artificially induced nerve signals follow ...
... electrodes translate sounds into electric stimulation of the vestibulocochlear nerve – artificially induced nerve signals follow ...
The Eye
... Convex lenses refract light in a towards each other Divergent waves are rays of light that diverges light that is traveling parallel to their principal axis; travels through the center of either lens,straight through and is not refracted Concave lenses refract parallel light rays away from each othe ...
... Convex lenses refract light in a towards each other Divergent waves are rays of light that diverges light that is traveling parallel to their principal axis; travels through the center of either lens,straight through and is not refracted Concave lenses refract parallel light rays away from each othe ...
Cones
... retina slowly becomes more sensitive to light ; pupil dilate – to capture more light into the retina, this decline in visual threshold is called dark adaptation. ...
... retina slowly becomes more sensitive to light ; pupil dilate – to capture more light into the retina, this decline in visual threshold is called dark adaptation. ...
The Eye - My Anatomy Mentor
... Excitation of Cones ◦ 3 types of Cones Each contains a pigment with a different opsin Each pigment is sensitive to a different wavelength of light Each detects a different color of light (red, green and blue) Breakdown and regeneration of visual pigments in the cones is the same as for rhodopsin T ...
... Excitation of Cones ◦ 3 types of Cones Each contains a pigment with a different opsin Each pigment is sensitive to a different wavelength of light Each detects a different color of light (red, green and blue) Breakdown and regeneration of visual pigments in the cones is the same as for rhodopsin T ...
43 Physiology of visual analyzer
... Rhodopsin (retinal + opsin) is the visual pigment of rods. The absorption of light by rhodopsin initiates a signal-transduction pathway Receptor potential is hyperpolization . ...
... Rhodopsin (retinal + opsin) is the visual pigment of rods. The absorption of light by rhodopsin initiates a signal-transduction pathway Receptor potential is hyperpolization . ...
Bird vision
Vision is the most important sense for birds, since good eyesight is essential for safe flight, and this group has a number of adaptations which give visual acuity superior to that of other vertebrate groups; a pigeon has been described as ""two eyes with wings"". The avian eye resembles that of a reptile, with ciliary muscles that can change the shape of the lens rapidly and to a greater extent than in the mammals. Birds have the largest eyes relative to their size in the animal kingdom, and movement is consequently limited within the eye's bony socket. In addition to the two eyelids usually found in vertebrates, it is protected by a third transparent movable membrane. The eye's internal anatomy is similar to that of other vertebrates, but has a structure, the pecten oculi, unique to birds.Birds, unlike humans but like fish, amphibians and reptiles, have four types of colour receptors in the eye. One of these receptors gives some species of birds the ability to perceive not only the range visible by humans, but also the ultraviolet part of the spectrum, and other adaptations allow for the detection of polarised light or magnetic fields. Birds have proportionally more light receptors in the retina than mammals, and more nerve connections between the photoreceptors and the brain.Some bird groups have specific modifications to their visual system linked to their way of life. Birds of prey have a very high density of receptors and other adaptations that maximise visual acuity. The placement of their eyes gives them good binocular vision enabling accurate judgement of distances. Nocturnal species have tubular eyes, low numbers of colour detectors, but a high density of rod cells which function well in poor light. Terns, gull and albatrosses are amongst the seabirds which have red or yellow oil droplets in the colour receptors to improve distance vision especially in hazy conditions.