You should wear goggles when mixing acidic solutions in order to avoid the acid from getting into your eyes. This is one of the many lab safety precaution practices that are carried out in the laboratory while performing experiments. The main purpose is to protect the eyes, mouth, nose, and the skill from contacting harmful substances such as acids and salts that can be toxic or irritators.
Other lab safety practices including wearing lab globes which are usually made of latex, wearing a lab coat so as to avoid spilling chemicals on the clothes, and closed shoes to protect the feet. Gas masks may also be used sometimes.