A light-emitting diode lamp includes an optically-transparent lens and an assembly. The lens includes a parabolic section defined about an axis and having a focus. The section includes a surface extending from the axis to a periphery of the section at a first end of the section, and a channel extending along the axis partially inside the section at a second end of the section. The assembly includes a chip and a dome. The chip is disposed in the channel at the focus of the section. The dome is disposed in the channel forming an interior space between the dome and the lens. The space is filled with an optically-transparent material having an index of refraction approximately equal to an index of refraction of the lens that eliminates or reduces effect of an optical interface between the material and the lens on direction of light emitted by the chip.