--%>

Define the terms astigmatism and presbyopia

Define the terms astigmatism and presbyopia?

E

Expert

Verified

Presbyopia is the visual impairment in which there is a loss of cililary muscle strength therefore dropping the capability of crystalline lens to adjust images of close objects onto the retina. In presbyopia, the near point of vision becomes more far-away. The disease usually takes place in old people. Astigmatism is caused by the irregular shape of refractive structures, mostly the cornea. In astigmatism, a single object-point might generate more than one image onto the retina and therefore the vision becomes distorted.

   Related Questions in Biology

  • Q : From which floral structure do fruits

    From which floral structure do fruits come?

  • Q : Incubation period of HIV How long is

    How long is incubation period of HIV? Describe briefly acute AIDS?

  • Q : Six Specific Trends of Organizational

    1) Declining productivity and the Japanese threat: the challenge is to reverse declining trends: ensuring better interplay between management approaches and techniques, and employees. 2) Revolution in middle management:  A big cut in the middle management cadre; restructuring and red

  • Q : Typical vegetation and typical fauna of

    Give a brief explanation of typical vegetation and typical fauna of temperate forests?

  • Q : Define Customer Loyalty Customer

    Customer Loyalty: The word customer loyalty is employed to explain the behavior of repeat customers, and also those that offer good reviews, ratings, or testimonials. Some of the customers do a particular company an immense service by providing favora

  • Q : Define Career Pathing Career Pathing :

    Career Pathing: It is the process employed by an employee to chart a course in an organization for his or her career path and career growth. Career pathing includes understanding what skills, knowledge, personal characteristics, and experience are nee

  • Q : Why is pH regulation significant for

    Why is pH regulation significant for living beings? How do mineral salts contribute in this regulation?

  • Q : Life duration of RBCs On an average

    On an average state the life duration of red blood cells? Where are they get destroyed? Specify the destination of heme groups after the destruction of hemoglobin molecules?

  • Q : Enzyme reverse transcriptase present in

    Which kind of virus is HIV? What is the enzyme reverse transcriptase present in the HIV?

  • Q : Problem on Pricing Strategy Prepare a

    Prepare a 4-5 page report, addressing the following: A) Determine and discuss a pricing strategy (penetration or skimming).B) Determine and discuss pricing tactics( product line pricing, value pricing, differential pricing, o