NEAR ADD

Question 1

what is presbyopia? what are some symptoms?

Answer 1

age related issue usually occurs around 40 yo
loss of lens flexibility/muscle tonus to focus at near.

blur vision at near, eye strain and headaches aft near work

Question 2

what are the steps for near add? how to refine ADD?

Answer 2

1. use donder’s table to estimate tentative ADD
2. ask px to hold reading material at comfortable reading distance and read
3. record the dist
4. perform +/- 0.25 binocularly **note that it is opposite of normal +/- 0.25, MIN PLUS AND MAX MINUS
5. introduce a -0.25 first, if better/same then give. if worse the give +0.25

Question 3

how to find range of clear vision? (near pt and far pt)

Answer 3

near point: ask px to move reading material closer until it just blurs and record the dist

far pt: ask px to move reading material further away until it just blurs and record the dist

Question 4

how should we refine the power of the ADD from here?

Answer 4

1. draw the line diagram
2. take far pt-near pt and the divide by 3 to find the intervals
3. mark the intervals and then mark where habitual reading distance lies
4. if it lies in the 1/3, add more + (power too weak)
5. if it lies in the 3/3, add more - (power too strong)