What strength magnifier do I need?

There are many types of magnifiers available.

It is very important that anyone using them understands and appreciates the potentials as well as the limitations of the full range available. Anyone with sight loss should have a low vision assessment before deciding on a magnifier.

You can find your nearest low vision clinic on the Sightline Directory by entering your postcode and the search words 'low vision clinic'.

Further information on magnifiers, including how to choose the best one for your needs can be found in our Top tips - magnifiers and Making the most out of your sight leaflet, part of our Starting out series:

Magnifier prediction chart

You can use our prediction chart to determine the level of magnification that you are likely to need in order to read newspaper size print:

Obviously this can only be used as a rough guide since many other factors, including the level of lighting or the strength of your current reading glasses, can affect the level of magnification needed.

When using the chart

  • Always wear your reading glasses, even if you have found them of little benefit in the past
  • Use a desk light to add additional light onto the page. For best results direct the light in front of you onto the prediction chart
  • Hold the chart at 25 centimetres (10 inches) from your eyes or at your preferred distance where you feel most comfortable and can see the chart easily
  • Starting with the largest print, read down the various print sizes until you find it too difficult. The smallest print size that you can comfortably read should then be used for your prediction
  • Look at the recommended lens power written on the right hand side below the last print size that you can read. For example if the smallest print size you can read at 25cm is N32, then you require approximately +16d (5x) magnification in order to read newsprint.

For further information and advice contact our Helpline:

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