It is essential that we choose the minimum level of magnification when using Low Vision Aids. This is because the power of a lens directly governs its size. In other words the stronger the power of a lens the smaller its size will be. There is no such thing as a large powerful magnifier. Furthermore as magnifiers get stronger their working distance gets shorter; the stronger the power of a lens the closer you have to hold it to your eye and the closer you have to hold the paper to the lens.

To establish the most appropriate power magnifier please download and print the "Prediction Chart" from this website. Hold the "Prediction Chart" approximately 25 cm (10") from your eyes. If you have a pair of reading glasses please use them - even if they are of little use to you now. 

Starting with the largest print, read down the various print sizes. Look at the recommended lens power undreneath the last print size that you can read (on the right hand side)

For example if the smallest print size you can read at 25cm is N32 then you require approximately +16d (5x) magnification.

To download the chart to your computer right click on the link below and then choose "Save Target as..." and select a drive and folder on your computer.

Prediction Chart

Please note to view the prediction chart you will need the free 'Adobe Reader' program installed on your computer. If you do not already have this program click on the link below to obtain a free download.