The purpose of this study was to quantify noninvasively, with the use of laser-flare meter, the alterations of the blood-aqueous barrier following phacoemulsification, extracapsular cataract extraction (ECCE), trabeculectomy and phacotrabeculectomy. Aqueous flare measurements were performed using laser-flare meter (Kowa FM-500). The device allows noninvasive, quantitative determination of aqueous protein concentration by recording the scatter of a helium- neon laser light scanned into the anterior chamber. Anterior chamber flare expressed as photon counts per millisecond was also estimated preoperatively, one and three days postoperatively, in two groups of cataractous eyes: 75 eyes after `divide and conquer' phacoemulsification with continuous curvilinear capsulorhexis, 43 eyes after extracapsular cataract extraction with `can opener' capsulotomy. Moreover, two groups of eyes following trabeculectomy (12 eyes) and phacotrabeculectomy (12 eyes) were also examined one, three and seven days postoperatively. We observed significantly lower anterior chamber flare measurements following phacoemulsification (32.0 - 1 day, 16.4 - 3 days postop) than after ECCE (64.6 and 40.2, respectively; P < 0.001 vs phaco group). Relatively high values were obtained after phacotrabeculectomy (58.0 one day, 39.3 - three days and 24.4 - 7 days postop). Intermediate values were noted after trabeculectomy alone (46.3, 25.6 and 23.9, respectively). Phacoemulsification with curvilinear capsulorhexis induced less severe blood-aqueous breakdown than ECCE with `can opener' capsulotomy. Eventually, it can be suggested that phacoemulsification, as a less traumatizing technique might be preferable in high risk eyes (with diabetes, glaucoma, uveitis) that are more susceptible to postoperative inflammation and consecutive complications.