That’s a really good question! Many people worry about the eye safety of bright light therapy.
You are absolutely correct to be concerned about UV light. Light from this non-visible part of the spectrum can cause a variety of eye problems, especially macular degeneration.
The good news is that most, legitimate light boxes include a diffuser screen that is designed to entirely block out this portion of the wavelength. This is another good reason to only use light boxes that have been clinically tested, both for effectiveness and safety.
That’s a really good question! Many people worry about the eye safety of bright light therapy. You are absolutely correct to be concerned about UV light. Light from this non-visible part of the spectrum can cause a variety of ocular problems, especially cataracts. The good news is that most, legitimate light boxes include a diffuser screen that is designed to entirely block out this wavelength portion. This is another good reason to only use light boxes that have been clinically tested, both for effectiveness and safety.
As early as 1990, we published a warning in the journal Photochemistry and Photobiology (vol. 51, pp. 781-792) that the use of tricyclic drugs can result in photosensitizing reactions in the presence of both ultraviolet light (UV below 400 nm) and visible light (up to about 550 nm, including the blue and green ranges). Such photosensitization could affect both skin and eye structures. Sunscreen would not protect your skin from light energy in the visible range, and obviously it would not protect your eyes in either UV or visible ranges. Although the manufacturer does not specifically list Tegretol as a photosensitizer, they do list side effects of both skin reactions and depression.
We do not know the specifics of your case — there could be various reasons for the skin reactions you report. Obviously, you should immediately test whether the reactions disappear when you stop using your light box, and whether the problem extends to outdoor sunlight exposure. You should promptly consult your dermatologist; receive a thorough ophthalmic exam (including slit-lamp fundoscopy and tonometry); and see your psychiatrist to review your drug dose, plasma level of the drug and blood chemistry screen, and consider other possible drug-drug interactions and alternate mood stabilizers.
When doctors advise patients to avoid sunlight, the risk factor is almost always ultraviolet (UV) radiation. As you can see from CET.org, an adequate light box should screen out UV, in which case there should be no UV risk. However, some light boxes screen out more UV than others, and boxes that use full-spectrum light bulbs present an additional challenge for adequate filtering. As a result, we can still see skin reddening and puffiness under filtered full-spectrum light, which is not good. CET recommends a light box with a polycarbonate diffusing screen and a lower color temperature (4000 Kelvin) than used in full spectrum boxes (5500 Kelvin and above). Unless your dermatologist wants you to avoid blue light as well as UV, this apparatus should suit your need.
It is unnecessary to add UV glasses when using a light box that has filtered out UV at the 99%+ level. Tinted UV glasses will actually reduce the level of therapeutic light you receive. That said, however, some light box manufacturers claim to filter out UV when in fact their devices fall short of the 99%+ level. In such cases, clear UV glasses would protect the eyes, but not the skin. In our experience, the only screens that do the job perfectly use polycarbonate or OP-3 diffusers. Check manufacturers’ specs!
As best we know, the mechanism of action of light therapy for SAD is through visible (not UV) light to the retina of the eye (not the skin). Addition or subtraction of UV light using standard light boxes makes no difference in the antidepressant effect. Beyond this, cumulative UV exposure to the eyes or the skin presents well-known health hazards, and thus it should be avoided when seeking relief from SAD. Indeed, it is important to ascertain that any light box used for SAD treatment maximally filters out UV (and there are several on the market that fail to do so).
Your eye doctor is simply wrong. There is no known antidepressant benefit of UV radiation in combatting SAD. The antidepressant effect occurs fully in the visible range of light wavelengths. A popular impression — thanks to unscrupulous vendors — is that “full-spectrum” fluorescent bulbs, which are designed to emit UV and a high balance of far-blue wavelengths, are somehow especially effective for treating SAD. Wrong, and we advise against using them. These bulbs are inefficient, very expensive, and produce less lux per kilowatt hour than fully effective bulbs (see ww.cet.org/store). Don’t worry about your contact lenses, and please correct your doctor.