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

Respiratory lining of human lung, Normal 0 false false fals...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the use of vitamin a dry powder, Vitamin A dry powder Vitamin A...

Vitamin A dry powder Vitamin A dry powder is used in the (manufacture of dry mixtures) for which the oily ester concentrates are unsuitable or undesirable. Mainly, they are inc

Pre and post-operative nursing care of a child, Pre-operative and Post-oper...

Pre-operative and Post-operative Nursing Care of a Child with Cleft Lip: We shall begin with pre-operative nursing care and then focus on post-operative care. As you know that

Peste des petits ruminants (ppr), Peste des petits ruminants (PPR) is an a...

Peste des petits ruminants (PPR) is an acute, highly contagious viral disease of goats and sheep caused by peste des petits ruminants (PPR) virus which belongs to the genus Morbil

Determine the food sources of pyridoxine, Determine the Food Sources of Pyr...

Determine the Food Sources of Pyridoxine? Raw foods contain more of this vitamin than cooked foods. The food sources include: 1. Rich sources: Rice polishing s, wheat bran,

What is thyroid disease, Q. What is thyroid disease? Thyroid disease: T...

Q. What is thyroid disease? Thyroid disease: Thyroid disease is associated with angina. Anginas pectoris presents itself in the form of speific symptoms which tend to re- oc

Extremes of heat and cold, Extremes of Heat and Cold Deserts are region...

Extremes of Heat and Cold Deserts are regions of aridity with rainfall of less than 20 cm per year and the soil, though L, fertile, is too porous to retain any water. In summer

What is the vector of malaria, What is the vector of malaria? How different...

What is the vector of malaria? How different is its behavior from the behavior of the vector of dengue fever? The vector of malaria is a mosquito of the genus Anopheles, also k

Name the animals having a single opening as mouth and anus, One example of ...

One example of animals having a single opening to the outside that serves both as mouth as well as anus is: 1. Octopus 2. Asterias 3. Ascidia 4. Fasciola Ascidia i

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