Is wearing sunglasses indoors bad for your eyes? What actually happens

Wearing sunglasses indoors does not damage your eyes. There is no ultraviolet to block inside, and the eye is not harmed by seeing less light. The one genuine effect is dark adaptation: after an hour behind a dark lens, your eyes have adjusted to the dimness, and ordinary indoor light feels uncomfortably bright for a few minutes when you take them off. That is temporary and harmless. The claim that sunglasses indoors weaken the eyes, make them dependent on tinted lenses, or cause any lasting sensitivity has no evidence behind it. What is true is that some people wear them inside for good medical reasons, and the rest of us have no reason not to if we want.

What actually happens

Your eyes adjust to the light they are in. In bright light the pupil narrows and the retina's sensitivity drops; in dim light the pupil widens and sensitivity rises. Behind a dark lens indoors, your eyes settle into a dim-light state. Take the lens off and, for a minute or two, the room is too bright. That is the whole effect. It reverses as fast as it arrived.

There is no mechanism by which this becomes permanent. The eye does not lose the ability to handle light by being spared it for an afternoon, any more than a muscle atrophies from a nap.

The myths

"Sunglasses indoors weaken your eyes." No. Eye muscles are not strengthened by bright light and not weakened by shade.

"You become dependent on them." Dark adaptation can make bright light briefly unpleasant, so people reach for the glasses again, and that loop can feel like dependence. It is a habit, not a physiological change, and it breaks the moment you spend an hour without them.

"They cause light sensitivity." They can make existing light sensitivity feel worse when removed, by the adaptation effect. They do not create it.

"Your pupils get stuck wide." No. The pupil responds to light within a second.

Good reasons to wear them inside

Migraine. Light sensitivity is a core migraine symptom, and many people with migraine find bright or fluorescent light a trigger. Tinted lenses indoors are a recognised part of managing it. Specific tints sold for migraine exist; a light grey or brown is often enough.

Photophobia from a medical cause. Corneal injury, some eye infections, uveitis, and recovery from eye surgery or dilating drops all make normal light painful. Sunglasses indoors are what an eye doctor will suggest.

Neurological and post-concussion conditions. Light sensitivity after a concussion is common and tinted lenses help.

Bright interiors. A glass atrium, a conservatory, an airport concourse at noon. Some indoor spaces are brighter than an overcast day outside, and there is nothing odd about a lens in them.

When to see someone

Light sensitivity that is new, severe, or comes with eye pain, redness, blurred vision or headache is a reason to see an eye doctor, not a reason to buy sunglasses. The sunglasses will make it more comfortable; they will not tell you why it is happening.

Which lens, if you do

For indoor wear, a light tint. If the reason is screen glare rather than light sensitivity, our blue light post explains why a tinted lens is the wrong tool for that. Category 1 or 2, in the terms our lens categories post explains: enough to take the edge off, not so dark that you cannot read a face. Grey keeps colours true. Polarization is irrelevant indoors, since there is no glare off flat outdoor surfaces, and it can make LCD screens look dim; our screen post explains why. A non-polarized light tint is the sensible indoor lens, and it is not what we sell; every pair on this site is a polarized outdoor lens.

Frequently asked questions