Text Box: THE OPTICAL CHANGES OF THE INTRAOCULAR ARTIFICAL LENSES SURFACE BEING IN CONTACT WITH SILICONE OIL AFTER CHILDREN’S CATARACT EXTRACTION AND VITRECTOMY Raczynska K1, Prokopowicz M2, Lukasiak J2, Iwaszkiewicz-Bilikiewicz B1 1Ophtalmological Department, Medical University of Gdansk, Poland 2Department of Physical Chemistry with Laboratory of Instrumental Analysis, Medical University of Gdansk, Poland Artificials intraocular lenses (IOL) are optical implants designed to replace the human crystalline lens. In cataract surgery the IOL are implanted in treatment of: congenital cataract, juvenile cataract, traumatic cataract (often in juvenile patients). Traumatic cataract is accompanied with retinal detachment very often. Vitroretinal surgery with silicone oil endotamponade is made in several cases of traumatic cataract. Usually silicone oil is indispensable supplement of vitreoretinal procedures. The physicochemical basis of the interaction of silicone oil with IOL materials is incompletely understood. In our work three types of lenses: heparin-surface modified lens (HSM), polymethylmethacrylate lens (PMMA), hydrogel lens were incubated in silicone oil through 20 weeks. The spectral analysis (transmitation VIS) of each IOLs was researched in 2-weeks intervals. Our results indicated that the HSM and PMMA are the most inert to silicone oil. However our date demonstrate that the interaction of silicone oil is greatest with hygrogel IOL. Based on a study, we determined that silicone oil should not be used in eyes in which a hydrogel IOL is already in place. VIS spectral analysis characteristic of each IOL was measured by HP 8452A Diode Array spectrophotometr UV/VIS (Hewlett Packard). 1848