Discuss the eight demand states with respect to bifocal lenses for glasses

What will be an ideal response?

Student answers will vary, but a possible answer includes the following:
• negative demand — many people don't want to admit they need bifocals
• nonexistent demand — when bifocal lenses were first introduced, people didn't know they existed
• latent demand — before they were introduced, many people thought such a product would be nice, but didn't think it would ever exist
• declining demand — this will occur when something better and more convenient is invented
• irregular demand — the consumer perceives a need for eye care devices only periodically, possibly when they begin to have trouble with their vision
• full demand — the manufacturers of the lenses are making all they possibly can
• overfull demand — the manufacturers of the lenses can't make enough and inventories are low
• unwholesome demand — seeking alternatives that can lead to undesirable consequences.