Can you explain myopia and hypermetropia, Biology

Assignment Help:

Q. How can the visual deficiencies known as myopia and hypermetropia be optically explained?

Myopia is the visual condition in which the images are formed previous to (in front of) the retina. Hypermetropia is the visual condition in which the point of image formation is further than (behind) the retina. Actually myopia is due to an increase in the distance between the crystalline lens and the retina, generally caused by a slight flattening of the eyeball and in hypermetropia the retina is too close to the crystalline lens due to slight shortening of the eyeball.

In myopia the far point and the near point of vision come closer (the refractivity of the crystalline lens that corresponds to the maximum distension capacity of the ciliary muscles isn't enough to provide visual accommodation). In hypermetropia the ciliary muscles aren't able to contract more to compensate the inadequate position of the retina that is the near point becomes more distant.


Related Discussions:- Can you explain myopia and hypermetropia

Other complications of prosthetic valves, Other Complications of Prosthetic...

Other Complications of Prosthetic Valves :  One of the dreaded complications of mitral valve replacement is ventricular rupture. It is difficult to manage and so it is better avoi

Give three examples of reflex actions, Give three examples of reflex action...

Give three examples of reflex actions. Examples of reflex actions are alter in size of the pupil of the eye in response to light intensity, blinking in response to foreign par

Explain etiology and clinical feature of parkinson''s disease, Explain the ...

Explain the Etiology and Clinical Features of Parkinson's disease? The cause of Parkinson's is unknown. Genetic predisposition (in most cases the reason for the death of these

Explain the food applications of guar, Explain the Food Applications of gua...

Explain the Food Applications of guar Guar imparts smoothness to ice cream by promoting small ice crystals during the freezing process. Guar gum in the dressing of cot

Potassium ions maintain the resting potential of neuron, Q. How do the pota...

Q. How do the potassium and sodium ions maintain the resting potential of the neuron? The plasma membrane of the neuron when at rest maintains an electric potential difference

What is cold-shortening, What is cold-shortening It is important to poi...

What is cold-shortening It is important to point out that over-effective chilling of hot carcasses can lead to toughness. If the temperature of the meat (muscles) can be reduce

Nitrogen cycle, Nitrogen Cycle The nitrogen is an essential constituen...

Nitrogen Cycle The nitrogen is an essential constituent of protein - the building block of all living cells. It is also a major constituent of the atmosphere (79 per cent). Al

Evolution, describe the two scientific models for evolution (gradualism, pu...

describe the two scientific models for evolution (gradualism, punctuated equilibrium)

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