Why does wearing sunglasses indoors backfire?
Because your eyes adapt to the lower light level. If you wear sunglasses indoors, normal light will subsequently be perceived as even brighter than before. You lower your threshold instead of alleviating your symptoms.
It is one of the most logical reflexes when experiencing light sensitivity, and at the same time, one of the few that will worsen your situation in the long run. In the short term, it feels better, and that’s what makes it so deceptive.
What exactly happens?
Your retina adjusts itself to the average amount of light it receives. If you artificially keep that amount low, the system becomes more sensitive to anything above it.
That's the same adaptation you experience when you step out of a dark cinema into the light. However, with daily use of sunglasses indoors, it doesn't last just a moment; it becomes your new normal.
What is the difference with a filter?
Sunglasses dim everything evenly, whereas a selective filter only removes the part you are sensitive to. As a result, the overall light level remains high enough not to provoke that adaptation.
| Sunglasses indoors | Selective filter | |
|---|---|---|
| What it does | Everything darker | Only the sensitive range |
| Contrast | Decreases | Maintained |
| Adaptation of your eyes | Sensitivity may increase | No cause for it |
| Usable indoors | Not recommended | Yes |
Which part of the spectrum that sensitive range exactly is, is explained in photophobia with migraine.
Does this mean you should never wear sunglasses?
Outdoors, yes, and preferably so. The advice applies exclusively to wearing them indoors as a fixed habit for light sensitivity.
Outdoors, bright sunlight is a reason to dim. Indoors, that is rarely the case, and it is precisely there that the habit arises that perpetuates the problem.
What can you do instead?
Reduce the light component that causes pain and leave the rest intact. This is precisely what the FL-41 filter was developed for.
Our RELIEF tempers the blue-green range without darkening your vision, allowing you to wear it indoors without provoking that adaptation. If that doesn't work, then your cause lies elsewhere, and darker glasses won't be your answer either.
This article is intended as an explanation, not as medical advice. For persistent light sensitivity, a general practitioner, neurologist, or ophthalmologist is the appropriate contact.
