Columbia College Physiology Sensory Lab printable pdf download

Physiology Sensory Lab

Student: _______________________________

Date: ________________________

Activity: Visual Tests and Experiments

The Blind Spot

Use the paper with the dot and + for this part of the lab. Tape the paper to the wall so that the + is on

the right side. Stand about arms length from the paper so that your left eye is directly in front of the +

Cover your right eye while fixing your gaze of the left eye on the +. Now carefully move toward the

paper and using your peripheral vision, stop moving when you observe that the dot will disappear.

Measure the angle formed between the + your left eye and the dot. Continue to slowly move toward the

paper and observe that the dot reappears. Repeat for the other eye reversing the positions described

above. Record your results below.

Angle using the left eye: ___________

Angle using the right eye: ___________

Explain why the dot disappeared at those angles

Visual Acuity

Have your partner stand 20 feet from the posted Snellen eye chart and cover one eye. As your partner

reads the lines, check for their accuracy. Record the line with the smallest-sized letters read. If itis

20/20 then the subject vision is normal. If the vision is recorded as any thing with a ratio less than one,

20/40 for example, then the vision acuity is recorded as less than normal. If the visual acuity ration is

greater than one, then the subject has better than normal vision. Record your observations.

Right eye:_____________________________

Left eye:______________________________

Astigmatism

The astigmatism chart tests for defects in the refracting surfaced of the lens and/or cornea. View the

chart first with one eye, then the other. Focus on the center of the chart. If all the radiating lines appear

equally dark and distinct, your refracting surface surfaces are not distorted. If some of the lines are

blurred and appear less dark than others, then some degree of astigmatism is present. Record your

observations.

Right eye:_____________________________

Left eye:______________________________

Columbia College Physiology Sensory Lab