Using the 'over +0.75' MEM method, if MEM is +1.50, what tentative add should you RX?

Using the 'over +0.75' MEM method, if MEM is +1.50, what tentative add should you RX?

• A. +1.50 D
• B. +0.75 D
• C. +0.25 D
• D. +0.50 D

Answer: (B)

In this MEM approach to estimating a near add, you account for a built‑in offset when you use the “over +0.75” method. The MEM reading tends to overshoot the actual required add by about 0.75 diopters due to the testing setup and near accommodative effort. So you subtract 0.75 D from the MEM result to get the tentative reading add. With MEM at +1.50 D, subtract 0.75 D to get a tentative add of +0.75 D. This is the best starting point before you refine with further near-vision testing.

In this MEM approach to estimating a near add, you account for a built‑in offset when you use the “over +0.75” method. The MEM reading tends to overshoot the actual required add by about 0.75 diopters due to the testing setup and near accommodative effort. So you subtract 0.75 D from the MEM result to get the tentative reading add.

With MEM at +1.50 D, subtract 0.75 D to get a tentative add of +0.75 D. This is the best starting point before you refine with further near-vision testing.