Perceptible
Part of speech: adjective
Definition: Able to be perceived, sensed, or discerned.
Noticeable
Part of speech: adjective
Definition: worthy of note; significantcapable of being seen or noticed
Example sentence: Another cause of change, one less noticeable but fundamental, is the modern growth of population closely connected with scientific and medical discoveries. It is interesting that the United Nations has set up a special Commission to study this question.