A light module includes one or more LEDs coupled to a circuit board, a lens disposed over at least one LED, and an adhesive layer disposed between each LED and the lens. A flange extends from at least one side of the lens. The adhesive layer fixes the lens in an optical alignment over the corresponding LED. The adhesive layer includes at least one of a non-permeable layer with an adhesive material on the top and bottom surfaces, a gas-permeable layer with an adhesive material on the top and bottom surfaces, a deposited material, and an over mold material. An alignment tool including one or more optical recesses and one or more alignment features is used in the assembly of at least one of an optical assembly and a light module that includes the optical assembly. The alignment tool facilitates precise alignment of the lenses over the LEDs.