Is the use of eye lid speculum in laser cataract surgery uncomfortable? A suction ring is used to dock to your eye in the process of the femtosecond laser. In the course of inserting the suction ring, the eye lid speculum must be used to hold apart the eye lids. The eye lid speculum surface is smooth and doesn’t cut or scratch your eyes. But is it comfortable? What is the diameter of the suction ring? To get answers to all such questions, click here.