To make the students aware of the need for eye safety in the classroom through

three mini labs.

Materials:

(part 1) Three styrofoam plates with a face drawn on each, a spray bottle of

acetone (nail polish remover), and a pair of glasses (use glass lenses).

(part 2) An overhead transparency, permanent marker, and an eyedropper.

(part 3) Obtain about 10 pig eyes from a friendly butcher shop, eight 25 ml.

beakers with 5 ml. of sulfuric acid, magnifying glasses, eyedroppers, a dish for

each eye, and a large amount of water.

Strategies:

(part 1) Treat each plate as a person cover one with plastic wrap and put the

glasses on him. Place him face up on a lunchroom tray and spray him with

acetone. The second plate put on the safety glasses and spray with acetone.

The third plate just spray with acetone.

(part 2) Draw a face with permanent marker on an overhead transparency. Draw in

each eye with a water soluble marker, for a dramatic effect paint the eyes with

phenolphthalein and let dry. Cover each eye with a contact lens disk cut from

extra transparency. For the actual class presentation place the face on the

overhead with contacts in place add a few drops of water to the edge of the

contact, use a mild sodium hydroxide solution for the face with the

phenolphthalein.

(part 3) After going over the results from the above aspects of eye safety place

the fresh pig eyes in small dishes and have teams of students observe the pupil.

Have one student carefully place 1-5 drops of sulfuric acid on the pupil, note

the time in seconds, create a commotion resembling PAIN, rush the pupil to a

water bath. After washing examine the pupil for damage.

Evaluation:

Have the students write a letter to a pen pal explaining what they have

learned, be explicit.

E-Mail

Rob Duncan

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