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

Explain the properties of gum arabic, Properties Gum Arabic is unique b...

Properties Gum Arabic is unique between the natural hydrocolloids because of its extremely high solubility in water and can yield solutions of up to 55% concentrations. Solutio

Calculate the volume of a 25% urethane, Assume that the blood volume of a r...

Assume that the blood volume of a rabbit is 0.5 liters. If the effective dose of the anesthetic urethane is 10 µgrams/ml of blood, calculate the volume of a 25% urethane solution t

Why is boiling used as a control, Substance A is being investigated to see ...

Substance A is being investigated to see if it is an enzyme. When substance A is mixed with substance B a reaction takes place. A control experiment is conducted using a sample of

Light and distribution, Light and Distribution We have mentioned in the...

Light and Distribution We have mentioned in the beginning that the variation in the amount of light generally affects the global and local distribution of plants and animals. L

Excretory system, What are the excretory organ in protozoa,coelenterates, i...

What are the excretory organ in protozoa,coelenterates, insects,spider,and arthropods

Properties of stem cells-pulp tissue revascularization, Properties of Stem ...

Properties of Stem Cells Stem cells are defined by having 3 major properties: 1) They are capable of self-renewal.  2) They divide, some daughter cells give rise to cells

Define modulation of transcription of cell cycle proteins, Modulation of th...

Modulation of the transcription of cell cycle proteins? The 1,25-(OH),D  compound (calcitriol), is present in the blood complexes to the vitamin D-binding  protein, a specific

Effects on materials - air pollutants, Effects on Materials - Air pollutant...

Effects on Materials - Air pollutants Most air pollutants are reactive chemicals, so they react with most of the substances around. You may recall from your chemistry lessons

Define burette - nutritional biochemistry, Define Burette - Nutritional Bio...

Define Burette - Nutritional Biochemistry A burette is a vertical cylindrical piece of laboratory glassware with a volumetric graduation on its full length and a precision tap,

Explain the biomechanics of cantilevers, Explain the biomechanics of cantil...

Explain the biomechanics of cantilevers The biomechanics of cantilevers need to be understood. It has been found that when a three unit prosthesis is supported by two implants

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