How to try out filters

Filters are about the patient’s experience and it is not possible to measure which one fits. Therefore, it is important to let the client try different filters and pay attention to the reaction. The most important question is:

How does this filter feel?

Comfort rather than visual acuity”

– Focus on comfort rather than visual acuity, says optometrist Jörgen Gustafsson. Jörgen has worked with filters since the first lenses were dipped in a colour 40 years ago and below are his tips for a successful assessment.

Jörgen´s tips

• Start from the individual in front of you – what are the needs of this person?

• Select a few filters to try on.

• Ask questions about comfort rather than visual acuity.

• Low contrast vision is more important than high contrast vision.

• Different lighting conditions create different needs – combine the selected filter with a polarising or photochromatic effect.

• Take the opportunity to talk about lighting.

• Also test up close.

• Let the patient borrow a cover frame to test the filter at home, both indoors and outdoors.

Bonus tip

If you want to show the difference between a selective filter, which absorbs parts of the light spectrum, and a coloured glass, which dims the entire light spectrum, you can let the patient test the two types, one after the other.

– I usually start the filter test by using one flirp with ML511 and one flirp with 50 % neutral grey. Both remove 50 % of the light but in two different ways. If there is a positive reaction to ML511, you can go ahead and compare it with different filters.”

If you want to perform this test often, you can order a flirp with this specific combination, or two different solutions for the client to try on.

Test material

Many people try out filters using flirps, but we also provide oculus rings and cover frames with different filter colours.