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

What are deciduous trees, What are deciduous trees? Deciduous trees are...

What are deciduous trees? Deciduous trees are plants that lose their leaves in a period of the year. In the case of the deciduous trees of the temperate forest the fall of the

Cellulose, Cellulose is a polysaccharide which is composed of the unbranch...

Cellulose is a polysaccharide which is composed of the unbranched chains of glucose; the major structural carbohydrate of the plants, insoluble in water, and indigestible in the h

What is the probability of carrier of the recessive allele, Two parents who...

Two parents who are each known to be carriers of an autosomal recessive allele have four children. None of the children has the recessive condition. What is the probability that

What substance is prepared from species of red algae, Name that gelatin-lik...

Name that gelatin-like substance which is prepared from different species of red algae growing in Asiatic waters. Prepared product appears in the form of cakes, coarse granules and

How do white cells differ from red cells, How do white cells differ from re...

How do white cells differ from red cells (a) In their structure, (b) Their function?   a) White cells have nuclei, red cells do not have nucle

How respiratory pigments act, Q. How respiratory pigments act? Respirat...

Q. How respiratory pigments act? Respiratory pigments are oxygen-carrying molecules present in the blood. When the oxygen concentration is high for instance, in the pulmonary a

Total artificial heart in circulatory assist devices, Total Artificial Hear...

Total Artificial Heart :  Jarvik seven was the first successful total artificial heart supporting the patient for 112 days. The disadvantage is that the patient has to be connecte

Height of plants - quantitative characters, Height of Plants - Quantitative...

Height of Plants - Quantitative Characters The height of a plant is a very good indicator of their general performance and therefore, can be employed as a criterion of the suc

Explain indications for surgery of total anomalous, Explain Indications for...

Explain Indications for Surgery of Total Anomalous pulmonary Venous Connection ? Once TAPVC is diagnosed in a neonate with symptoms, operation should be undertaken immediately.

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