A paranasal sinus access implant device (200, 630, 700, 800, 800', 970) useful for implantation in a human to fluidly connect a lacrimal apparatus to a paranasal sinus through a fistula formed between the lacrimal apparatus and the paranasal sinus, the implant device comprising: a proximal end (202, 716, 816) at a first longitudinal end of the device; a distal end (204, 634, 718, 818) at a second longitudinal end of the device that is longitudinally opposite the first longitudinal end; a conduit (208, 240, 250, 704, 804, 804') between the proximal end and the distal end; an internal passage (210, 738, 838) through the conduit; a length (714, 814) of the implant device longitudinally along the device between the proximal end and the distal end in a range of from 8 millimeters to 50 millimeters; and a width (740, 840) of the internal passage transverse to the length in a range of from 0.25 millimeter to 5 millimeters; characterized by the conduit including a first longitudinal portion (706, 806) and a second longitudinal portion (708, 808) located toward the distal end relative to the first longitudinal portion; wherein the first longitudinal portion of the conduit has a length of at least 3 millimeters, and the second longitudinal portion of the conduit has a length of at least 3 millimeters; the first longitudinal portion of the conduit having a first minimum wall thickness adjacent the internal passage; and the second longitudinal portion of the conduit having a second minimum wall thickness adjacent the internal passage that is smaller than the first minimum wall thickness, wherein the first minimum wall thickness is at least 0.05 millimeter larger than the second minimum wall thickness; the implant device configured to be implanted to fluidly connect the lacrimal apparatus to the paranasal sinus so that when implanted: the proximal end is disposed in the lacrimal apparatus; the distal end is disposed in the paranasal sinus; and the conduit is disposed through the fistula between the lacrimal apparatus and the paranasal sinus with at least a portion of each of the first longitudinal portion and the second longitudinal portion of the conduit disposed within the fistula and with at least a portion of the second longitudinal portion of the conduit disposed in the paranasal sinus. a proximal end (202, 716, 816) at a first longitudinal end of the device; a distal end (204, 634, 718, 818) at a second longitudinal end of the device that is longitudinally opposite the first longitudinal end; a conduit (208, 240, 250, 704, 804, 804') between the proximal end and the distal end; an internal passage (210, 738, 838) through the conduit; a length (714, 814) of the implant device longitudinally along the device between the proximal end and the distal end in a range of from 8 millimeters to 50 millimeters; and a width (740, 840) of the internal passage transverse to the length in a range of from 0.25 millimeter to 5 millimeters; characterized by the conduit including a first longitudinal portion (706, 806) and a second longitudinal portion (708, 808) located toward the distal end relative to the first longitudinal portion; wherein the first longitudinal portion of the conduit has a length of at least 3 millimeters, and the second longitudinal portion of the conduit has a length of at least 3 millimeters; the first longitudinal portion of the conduit having a first minimum wall thickness adjacent the internal passage; and the second longitudinal portion of the conduit having a second minimum wall thickness adjacent the internal passage that is smaller than the first minimum wall thickness, wherein the first minimum wall thickness is at least 0.05 millimeter larger than the second minimum wall thickness; the implant device configured to be implanted to fluidly connect the lacrimal apparatus to the paranasal sinus so that when implanted: the proximal end is disposed in the lacrimal apparatus; the distal end is disposed in the paranasal sinus; and the conduit is disposed through the fistula between the lacrimal apparatus and the paranasal sinus with at least a portion of each of the first longitudinal portion and the second longitudinal portion of the conduit disposed within the fistula and with at least a portion of the second longitudinal portion of the conduit disposed in the paranasal sinus. the proximal end is disposed in the lacrimal apparatus; the distal end is disposed in the paranasal sinus; and the conduit is disposed through the fistula between the lacrimal apparatus and the paranasal sinus with at least a portion of each of the first longitudinal portion and the second longitudinal portion of the conduit disposed within the fistula and with at least a portion of the second longitudinal portion of the conduit disposed in the paranasal sinus.