Hello!! This is the official blog of Joseph and Cindy! hehehe :)
For this activity, we tested several properties of the eye. The activities were repeated several times and the measurements obtained were averaged.
The first is we looked for the minimum distance that our eyes can focus. When an object approaches your eye, it becomes blurry. To measure this, we did it straightforwardly.
Measuring the Minimum Eye Focus Distance
We covered one of our eyes and focused on the details of the pen. It is then moved closer to our eye until the the details become blurry. That is, when it is no longer focused. After taking into account a small bias (~1cm as shown in the picture), the minimum focus distance can be determined. This was done for both of the eyes.
Minimum Focus Distance of Joseph and Cindy
We found out that our left and right eyes have slightly different minimum focus distances. Also, as seen from the graph Cindy can focus on an object much closer than Joseph. This can translate in the differences in our eye conditions.
Next, we tested how far our peripheral vision can reach. In our first attempt, we did this:
Failed Attempt?
Its not a complete failure actually. If we had calibrated it correctly, it might have worked. So, we moved on the the straightforward way again.
Measuring the Maximum Angle of Horizontal Peripheral Vision
We moved the pen as directed by the string until we cannot see it anymore. This was done for both left and right directions. Our hands were kind of distracting though since we might say that we can still see the pen while what we see really is our hand. So, we were careful of that.
We did a slightly different setup while measuring the limit of the vertical peripheral vision.
Measuring the Maximum Angle of Vertical Peripheral Vision
We placed a measuring tape on the blackboard and moved a horizontally oriented pen on it until we can no longer see it. This is done since wanted to make a triangle with one leg the distance of our eyes to the black board. We took note of the point right in front of us since we would measure where the pen stopped from there. This will be the other leg of the triangle. From there, we can compute for the angles. This was done for the upward and downward directions.
While we were moving the pen downwards, it was somehow distracting. Its as if our eyes want to look downwards at the pen.
Comparison of the Limits of our Peripheral Vision
From here, we can see that there is a very small difference on our peripheral vision. Although it seems that it doesn't follow what they say that women have a wider range of peripheral vision than men.
The horizontal limits of our peripheral vision is significantly larger than their vertical counterparts. This may have been an effect of evolution since back then, we should be wary of danger that may not be in our immediate direction where we are facing.
Next is Visual Acuity. We test here the clarity of objects as they move laterally away from our point of focus. The fovea is the part of our eye responsible for our capability to fine details in an object. It only has a small area in our eye and we can expect that it the area we will see in fine detail will be small too.
Testing Visual Acuity
An upside-down text was placed on the blackboard covered by white paper. There was a hole showing a relatively lengthy word. We would then cover it entirely except for one letter. We should focus on that letter only. Then, we would uncover the other letters without removing our eyes from the original letter until the last uncovered letter loses its detail. Knowing the distance of the paper to our eyes and the distance of the focused letter to the last uncovered letter, we can calculate the angle that encloses the small area that can be seen clearly while focusing on one point. Well, we can assume that that area is the area of a circle.
The results are as shown below.
If we look at the absolute values rather than the relative values of the angles, they are close to each other. And the corresponding solid angle indeed encloses a small area.
We now test what colors we will perceive as we (starting from dark) illuminate them. We placed colored strips of paper corresponding to the seven colors of the rainbow into a black bag. We must then look at them as light was slowly allowed to illuminate them. We were conscious of illuminating them evenly. Trying to keep the least amount of light in, we also covered it with a black trash bag. The colors we've seen are ordered below (1 being the first we've seen and 7 being the last):
Order of Seeing Colors from the Dark
Cindy went first and she didn't show the results beforehand to avoid any biases. But the results are still very similar!
It appears that we see the longer wavelength (red, orange, yellow, ...) of visible light first. The shorter wavelength (blue, violet, ...) of visible light however, was very hard to find. This may be explained when ma'am jing said that our eyes are more sensitive to green. That is, the longer wavelengths of light.
We were intrigued with what Ma’am Jing said about our eyes being able to white balance. That’s why we decided to design an experiment that would enable us to find out what is the perception of the human eye of white surface after exposure to different colors.
The experiment is very simple. A powerpoint presentation is made such that the slides are of different colors. After each colored slide is a white colored slide. A test subject is made to stare at one color for about 1 minute and then look at the proceeding white colored slide. Each perception of the white slide is listed. This is shown in the table below:
As we have observed, staring at a particular color for a long time and then looking at a white surface, that color’s complimentary color is seen before our eyes white balances.
We summarize our data with the figure below:
