State in detail about dark adaptation, Biology

Assignment Help:

State in detail about Dark Adaptation

Dark adaptation is a phenomenon by which retina and pupil react to decreased illumination. Test is performed using Goldmann-Weeke's adaptometer. Subjec't is pre- adapted to a standard amount of illumination and then presented with a series of light at 11" below fixation. Intensity of flashes is controlled by neutral density filter. Sensitivity curve is a bipartite curve, initial rapid phase represent cone function and second slower segment represent rod function. The inflection on the curve where the rod begins is known as rod cone break (alpha point) and in the healthy eye it occurs 7-10 minutes of dark adaptation. It is useful to detect Vitamin A deficiency, anoxia, tobacco, opacities, degenerations, myopia and glaucoma by this.


Related Discussions:- State in detail about dark adaptation

Explain acylglycerols, Explain acylglycerols The most abundant class of...

Explain acylglycerols The most abundant class of food lipids is the acylglycerols, also known as glycerol esters of fatty acids, which dominate the composition of depot fats in

Nonsurgical retreatment -secondary endodontic ttt, Nonsurgical retreatment ...

Nonsurgical retreatment (secondary endodontic ttt ) -Is the main difference between primary endodontic disease versus post treatment disease is the need to Regain access to

What is molecular weight, What is molecular weight? Molecular Weight ...

What is molecular weight? Molecular Weight :  The molecular weight of a molecule refers to the sum of the atomic weights of all the atoms making up the molecule. The gram mol

What is the type of meiosis that occurs in pteridophytes, How are gametes f...

How are gametes formed in the pteridophyte life cycle, by mitosis or meiosis? What is the type of meiosis that occurs in pteridophytes? In pteridophytes gametes are made by mit

Types of glials cells and their functions, Types of Glials Cells and their ...

Types of Glials Cells and their Functions In the nervous tissue, besides the nerve cells there is one other cell type -the neuroglia which is present in large numbers and occu

Biosphere, Biosphere Biosphere is that part of the earth where life can...

Biosphere Biosphere is that part of the earth where life can exist. It is a narfqy layer around the surface of the earth. If you visualise the earth to be the size of an apple

Limiting factor - ecosystem, Limiting Factor - Ecosystem In all ecosys...

Limiting Factor - Ecosystem In all ecosystems one factor, usually abiotic, limits the growth of organisms and is therefore called a limiting factor. The limiting factor is one

What are fossil fuels, What are fossil fuels? Fossil fuels, like oil, g...

What are fossil fuels? Fossil fuels, like oil, gas and coal, form when organic material is preserved from the complete action of decomposers, generally buried deep and under pr

Carbohydrates, Carbohydrates are the next important nutrients as they have ...

Carbohydrates are the next important nutrients as they have to perform a variety of functions such as: 1) Provide major source of energy 2) Breakdown of fatty acids and preve

Bjork-shiley valve (b-s)-types of valves, Bjork-Shiley Valve (B-S) : This...

Bjork-Shiley Valve (B-S) : This is one of the earliest types of tilting disc valves introduced in early 70's. The earlier models like concavo-convex disc valves were withdrawn fr

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd