Light transmission and ultraviolet protection of contact lenses under artificial illumination.
OBJECTIVE
To determine the spectral transmission of contact lenses (CLs), with and without an ultraviolet (UV) filter to evaluate their capacity for protection under UV radiation from artificial illumination (incandescent, fluorescent, xenon (Xe) lamps, or white LEDs (light-emitting diode)).


METHODS
The transmission curves of nine soft CLs were obtained by using a PerkinElmer Lambda 35 UV-vis spectrophotometer. A CIE standard was used for the emission spectra of incandescent and fluorescent lamps, and Xe lamps and white LEDs were measured by using an International Light Technologies ILT-950 spectroradiometer.


RESULTS
Five of the nine soft CLs analysed state that they incorporate UV filters, but the other four do not specify anything in this regard. The spectral transmission of all the CLs studied is excellent in the visible region. The CLs with UV filters filter out this radiation more or less effectively. Xe lamps emit a part in the UV region. Incandescent, fluorescent and white LEDs do not emit at all in the UV.


CONCLUSIONS
Incorporating UV filters is important when the illumination is from a Xe lamp since this light source emits in the UV region. This, however, does not occur with incandescent and fluorescent lamps or white LEDs. The CLs that do incorporate UV filters meet all the standard requirements that the U.S. FDA (Food and Drug Administration) has for UV-blocking CLs Class II (OcularScience, CooperVision and Neolens), and AcuvueMoist and HydronActifresh400 even comply with the stricter Class I. The CLs without UV filters let UVA, UVB and even some UVC through.
Depto de Óptica Facultad de Física. Universitat de València. C/Dr Moliner 50, 46100 Burjassot, Valencia, Spain; Fisabio Oftalmología Médica (FOM), Bifurcación Pío Baroja-General Avilés s/n., 46015 Valencia, Spain. Electronic address: Jose.Artigas@uv.es.
José M
JM
Artigas
Fisabio Oftalmología Médica (FOM), Bifurcación Pío Baroja-General Avilés s/n., 46015 Valencia, Spain.
Amparo
A
Navea
Fisabio Oftalmología Médica (FOM), Bifurcación Pío Baroja-General Avilés s/n., 46015 Valencia, Spain.
M Carmen
MC
García-Domene
Depto de Óptica Facultad de Física. Universitat de València. C/Dr Moliner 50, 46100 Burjassot, Valencia, Spain.
Andrés
A
Gené
Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, Moncada, Valencia, Spain.
Cristina
C
Artigas
D065638:Absorption, Radiation; D003263:Contact Lenses, Hydrophilic; D005374:Filtration / Q000295:instrumentation*; D008027:Light; D011835:Radiation Protection / Q000295:instrumentation*; D013057:Spectrum Analysis; D014466:Ultraviolet Rays
Artificial illumination; Contact lenses; UV radiation