Antler lamps are made from smaller antlers or broken pieces which are suitable for large antler light fixtures or furniture. Traditionally of course side lamps are generally bought in pairs to feature on each side of a bed or a sofa. If antler lamps are made from genuine antlers though, i.e. are not faux antlers, then natural antler lamps will never exactly match because antlers are not symmetrical in the wild.
If a slight mis-match in shape and size will annoy you then avoid buying pairs of antler lamps. Perhaps instead look for a single deer antler chandelier or other feature piece. Antler lamps are usually finished with a natural fabric shade - often rawhide or birch bark. Again these natural materials will never provide you with exactly matching shades.
There are also various accessories that you can buy for your antler lamp. Finials are popular, usually with brass fittings these vary in size from small burrs to large antler forks or points.
You may want to consider how easy a an antler light is to turn on and off if you are going to use them as a side lamp in a bedroom. Another option is to choose an antler wall scone. Scones can be mounted on various woods to blend with other joinery in the room and are certainly more practical if their are small children in the household.
Whatever you chose as far as antler lamps from a design point of view remember the practicalities of your design choices as well!