What is the Near Point for Your Vision?
The closest distance for distinct, clear vision without straining is called the near point.
Discover Your Vision’s Near Point
Materials:
book or page with print
flexible measuring tape
1. Hold an open book close but not touching your face.
2. With both eyes open, slowly move the book away from your face. Stop when you can read the print on the page. Then, move the book toward and away from your face to find the best distance where you can read the print with no strain.
3. Measure the distance from the book to your eyebrow.
- Note: The image shown features a ruler, but a flexible measuring tape might be a safer way to measure this distance without a possible eye injury.
The near point is the closest distance that an eye can focus on. An optometrist checks this by moving a printed sheet toward your eyes and asking you to say when the sheet is easiest to read. The near point for “Normal” vision is 10 in (25 cm).
This simple near point vision distance experiment was taken from:
Janice VanCleave’s Biology for Every Kid
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Clues for developing a simple experiment into a science project.
Science Project Question:
1. Does age affect near point vision distance? In other words, does age affect how far away something has to be held in order to read it?
Note that these questions identify cause/effect variables.
Age is being considered as possibly affecting near point vision distance.
- What is possibly being affected: near point vision distance
- What might cause near point vision distance to be affected: Age
The bottom line is that science projects entered into the science fair are expected to be more than a simple experiment. Instead, science fair projects are expected to be cause/effect experiments. Following are examples of questions for a simple experiment and a cause/effect experiments.
Simple Experiment: What is your near point distance?
Cause/Effect Experiment: What affect does age have on near point vision distance?
Notice that the Cause/Effect example is stated so the answer requires more than a yes or no answer.
Example Hypothesis:
Based on the fact that I see older people at church holding their song books as far away as possible, I predict that near point vision distance increases as age increases.
Experiment to Test the Hypothesis
Clues:
1. Use the procedure above to measure the near point vision distance for different ages.
2. Design a chart to record the distance measurements and ages. This recorded results is called data.
3. The more data collected the more credible will be the conclusion for this project.
4. A control experiment is a standard you will compare your data with. For this project, select the median age and its near point distance as the control.
For example: The median age of {10, 11, 13, 15, 16, 23, 26, 30, 40, 50, 55} would be the middle number in the set, which is 23. If there are two middle numbers, average them.
5, Analyze the results and write a conclusion that states your hypothesis and whether your experimental results does or doesn’t supports your hypothesis.
