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

Piciculture, PROJECTS THAT HAVE TO BE DONE IN SCHOOL ABOT PICICULTURE

PROJECTS THAT HAVE TO BE DONE IN SCHOOL ABOT PICICULTURE

Counselling at diagnosis, Q. Counselling at Diagnosis? A newly diagnose...

Q. Counselling at Diagnosis? A newly diagnosed case of diabetes will have lots of questions and will be confused regarding the treatment and complications of the diabetes. It i

Very low density lipoproteins, Triglyceride and cholesterol synthesized in ...

Triglyceride and cholesterol synthesized in the liver are secreted in very low density lipoprotein (VLDL) particles which serve to transport the lipids to the periphery. VLDL form

Cold chain system, Cold Chain System Vaccines are sensitive to heat. ...

Cold Chain System Vaccines are sensitive to heat. On exposure to heat their potency is lost. Once a vaccine has lost its potency it cannot be regained, so it is important

Simple tips to diarrhoea patient, A few simple tips which should be given t...

A few simple tips which should be given to the patient. • Boiling, steaming, baking, pressure cooking should be encouraged • Consume small and light meals frequently instea

Parthenocarpy, Parthenocarpy It is generally observed that the fruit d...

Parthenocarpy It is generally observed that the fruit develops after fertilization and it has fertile seeds inside it. However, this is not always so. Fruits of certain variet

Describe the effects of acid precipitation on ecosystems, What are the effe...

What are the effects of acid precipitation on ecosystems?

Types of embryogeny, Types of Embryogeny On the basis of the plane of...

Types of Embryogeny On the basis of the plane of division of the zygote and of the cells of the 2-celled proembryo, and also taking into account the relative contributions of

Define hydroxybenzoic acid and hydroxycinnamic acid, Define Hydroxybenzoic ...

Define Hydroxybenzoic acid and Hydroxycinnamic acid? Hydroxybenzoic acid: e.g. ellagic and gallic acids, which are hydrolyzable tannins, present in berries and nuts. Hydroxy

Discuss in brief about maxillary sinus, Discuss in brief about maxillary si...

Discuss in brief about maxillary sinus In normal conditions, the maxillary sinus maintains a close relationship with the alveolar ridge associated with second premolar and fir

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