20130213

Online reading assignment: corrective optics, magnifiers

Physics 205B, spring semester 2013
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on corrective optics and magnifiers.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"How lenses can be used to correct defects in vision by determining the compensation that needs to be made to help the eye focus on the desired object; the resulting measurement is measured in diopters."

"I liked finding out what my contact prescription means!"

"I found the magnifier concept that was in the notes very interesting because the angular magnification is the ratio of angular size as when you look at a magnifier compared to the angular size of what you see with the naked eye."

"Learning about the different types of prescription lenses, because I am one of the only members in my family who doesn't wear glasses."

"I like the optical illusions of Ames room because I have been in a room sort of like this and it is a cool experience."

"Trufocals glasses are really cool! I've always thought they should make glasses like that."
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"Lenses in combination confuse me. I had some trouble with only one lens, and now there are several."

"I don't understand what it means when using a magnifier when it says 'the final image is formed at infinity.'"

"A virtual image from a first lens being the object for a second lens--that's just crazy."

"Four years of post-graduate optometry school were condensed into a short presentation. Why does learning optometry take so long?"

"Determining if something is enlarged or diminished."
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"How can I make an appointment for office hours?" (For regularly-scheduled office hours, just show up. Otherwise e-mail me to arrange an appointment for other times during the week.)

"Can you go over the corrective optics for farsighted and nearsighted vision...do they both just form a virtual image for the eye?" (Yes, and yes.)

"Do we get to look through any optical instruments like microscopes or telescopes?" (Yes, next week in class there will be opportunities to look through compound microscopes, and refractor telescopes.)

"How does astigmatism in eyes affect vision, and how do contact lenses for astigmatism differ from typical contact lenses?" (Astigmatic eyes have different curvatures vertically versus horizontally, so eyeglasses must have different shapes vertically versus horizontally. Recently, weighted contact lenses can maintain a fixed orientation to correct for different vertical versus horizontal curvatures.)

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