Physics Project
PHYSICS PROJECT
TO STUDY THE OPTICAL LENS OF A HUMAN EYE
Eyes are organs that detect light, and convert it to electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement. In higher organisms the eye is a complex optical system which collects light from the surrounding environment; regulates its intensity through a diaphragm; focuses it through an adjustable assembly of lenses to form an image; converts this image into a set of electrical signals; and transmits these signals to the brain, through complex neural pathways that connect the eye, via the optic nerve, to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system.[1] Image-resolving eyes are present in molluscs, chordates and arthropods.[2]
The simplest "eyes", such as those in microorganisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms. From more complex eyes, retinal photosensitive ganglion cells send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to effect circadian adjustment. Contents[hide] * 1 Overview * 2 Evolution * 3 Types of eye * 3.1 Normal eyes * 3.2 Pit eyes * 3.2.1 Spherical lensed eye * 3.2.2 Multiple lenses * 3.2.3 Refractive cornea * 3.2.4 Reflector eyes * 3.3 Compound eyes * 3.3.1 Apposition eyes * 3.3.2 Superposition eyes * 3.3.3 Parabolic superposition * 3.3.4 Other * 3.3.5 Nutrients of the eye * 4 Relationship to life requirements * 5 Visual acuity * 6 Perception of colours * 7 Rods and cones * 8 Pigmentation * 9 See also * 10 References * 10.1 Notes * 10.2 Bibliography * 11 External links |
[edit] Overview
Eye of the wisent, the European bison
Complex eyes can distinguish
TO STUDY THE OPTICAL LENS OF A HUMAN EYE
Eyes are organs that detect light, and convert it to electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement. In higher organisms the eye is a complex optical system which collects light from the surrounding environment; regulates its intensity through a diaphragm; focuses it through an adjustable assembly of lenses to form an image; converts this image into a set of electrical signals; and transmits these signals to the brain, through complex neural pathways that connect the eye, via the optic nerve, to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system.[1] Image-resolving eyes are present in molluscs, chordates and arthropods.[2]
The simplest "eyes", such as those in microorganisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms. From more complex eyes, retinal photosensitive ganglion cells send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to effect circadian adjustment. Contents[hide] * 1 Overview * 2 Evolution * 3 Types of eye * 3.1 Normal eyes * 3.2 Pit eyes * 3.2.1 Spherical lensed eye * 3.2.2 Multiple lenses * 3.2.3 Refractive cornea * 3.2.4 Reflector eyes * 3.3 Compound eyes * 3.3.1 Apposition eyes * 3.3.2 Superposition eyes * 3.3.3 Parabolic superposition * 3.3.4 Other * 3.3.5 Nutrients of the eye * 4 Relationship to life requirements * 5 Visual acuity * 6 Perception of colours * 7 Rods and cones * 8 Pigmentation * 9 See also * 10 References * 10.1 Notes * 10.2 Bibliography * 11 External links |
[edit] Overview
Eye of the wisent, the European bison
Complex eyes can distinguish