A portable electronic device comprising: a housing; a front cover (929, 1100) coupled to the housing and defining a front side of the portable electronic device; a display stack below the front cover and comprising a plurality of display layers configured to produce a graphical output in a display region of the display stack, the graphical output visible through the front cover; and a light sensor module positioned at least partially within the housing and coupled to the display stack in the display region, the light sensor module configured to: receive ambient light passing through the front cover and through the plurality of display layers; and while a blanking interval is positioned over the light sensor module, produce an output corresponding to the received ambient light, the portable electronic device configured to determine an ambient light value based at least in part on the output from the light sensor module; wherein: the display stack comprises a first set of electrodes and a second set of electrodes; in an area above the light sensor module, a first electrode of the first set of electrodes overlaps a first electrode of the second set of electrodes; and in an area remote from the light sensor module, a second electrode of the first set of electrodes does not overlap a second electrode of the second set of electrodes. a housing; a front cover (929, 1100) coupled to the housing and defining a front side of the portable electronic device; a display stack below the front cover and comprising a plurality of display layers configured to produce a graphical output in a display region of the display stack, the graphical output visible through the front cover; and a light sensor module positioned at least partially within the housing and coupled to the display stack in the display region, the light sensor module configured to: receive ambient light passing through the front cover and through the plurality of display layers; and while a blanking interval is positioned over the light sensor module, produce an output corresponding to the received ambient light, the portable electronic device configured to determine an ambient light value based at least in part on the output from the light sensor module; wherein: the display stack comprises a first set of electrodes and a second set of electrodes; in an area above the light sensor module, a first electrode of the first set of electrodes overlaps a first electrode of the second set of electrodes; and in an area remote from the light sensor module, a second electrode of the first set of electrodes does not overlap a second electrode of the second set of electrodes. receive ambient light passing through the front cover and through the plurality of display layers; and while a blanking interval is positioned over the light sensor module, produce an output corresponding to the received ambient light, the portable electronic device configured to determine an ambient light value based at least in part on the output from the light sensor module; wherein: the display stack comprises a first set of electrodes and a second set of electrodes; in an area above the light sensor module, a first electrode of the first set of electrodes overlaps a first electrode of the second set of electrodes; and in an area remote from the light sensor module, a second electrode of the first set of electrodes does not overlap a second electrode of the second set of electrodes. the display stack comprises a first set of electrodes and a second set of electrodes; in an area above the light sensor module, a first electrode of the first set of electrodes overlaps a first electrode of the second set of electrodes; and in an area remote from the light sensor module, a second electrode of the first set of electrodes does not overlap a second electrode of the second set of electrodes.