--%>
Assignment Help - homework help

Description of presbyopia and astigmatism

Give a brief description of presbyopia and astigmatism?

E

Expert

Verified

Presbyopia is visual impairment in which there is loss of cililary muscle strength thus reducing the ability of crystalline lens to adjust images of near objects on retina. In presbyopia the near point of vision becomes more distant. The disease generally takes place in old people.

Astigmatism is caused by the irregular shape of refractive structures, mainly cornea. In astigmatism a single object-point might create more than one image on retina and so the vision becomes distorted.

   Related Questions in Biology

  • Q : Define the term Infrastructure

    Infrastructure: The fundamental physical systems of a nation or business. Communication, transportation, sewage, water and electric systems are all illustrations of infrastructure. Such systems tend to be high-cost investments; though, they are vital

    		•
  • Q : Define Internet Advertising Internet

    Internet Advertising: Nowadays Internet is one of the easiest ways to advertise which in turn helps marketers to consume. There are certain rules that need to be followed and applied as alike to other forms of advertising. Those rules will help busine

    		•
  • Q : Function of keratin in epidermis State

    State the function of keratin in epidermis?

    		•
  • Q : Describe what do protozoans eat

    Describe what do protozoans eat? Do they move in the search for food?

    		•
  • Q : What is Conflict resolution Conflict

    Conflict resolution: Fate of most of the organization all over the world depends on how effectively they communicate internally. This case becomes more relevant because it is the case of change management. One of the most beautiful arts of management

    		•
  • Q : Illustrate the term interferons

    Illustrate the term interferons?

    		•
  • Q : Blood vessels carrying venous and

    Which blood vessels carry venous blood to the heart and collects arterial blood from the heart?

    		•
  • Q : What is endosymbiotic hypothesis What

    What is endosymbiotic hypothesis regarding the origin of mitochondria? What are the molecular facts which support the hypothesis? To which other cellular organelles can hypothesis too be exerted?

    		•
  • Q : How nervous tissue distributed in

    How nervous tissue distributed in cnidarians?

    		•
  • Q : Question on sales tax Sales tax of $1

    Sales tax of $1 per unit of output is impose to the any firm whose product sells for $5 in a competitive industry. Will there be any entry or exit? If the tax is placed on single firm, that firm will go out of busi

    		•