An LED light bulb includes a thermally conductive base and at least one LED assembly disposed on the base. The LED assembly includes at least one LED configured to emit light. A thermal optical diffuser defines an interior volume of the LED light bulb. The LED is arranged to emit light into the interior volume and through the thermal optical diffuser. The thermal optical diffuser extends from the base to a terminus on a light emitting side of the LED assembly. The thermal optical diffuser includes one or more openings. An array of optical elements is disposed within the interior volume and is configured to focus the emitted light toward the openings. The thermal optical diffuser and the array of optical elements are arranged to allow convective air flow between the interior volume of the thermal optical diffuser and ambient environment.