The Math in Eye Glasses. Kate McCauley GED 613 Math Notebook.
Math in the World Around UsWhen deciding upon a subject for my math notebook, I chose an everyday item that I was familiar with-eyeglasses. Both my grandfather and father are optometrists and I spent a lot of time around glasses growing up. Upon taking a closer look, I was surprised to find so many examples of math around glasses. Here are some of those examples:
That’s 741 years ago!
Pure silica has a "glass melting point“ of over 2300 °C (4200 °F). It can be made into glass, but other substances are added to simplify processing. One is sodium carbonate, which lowers the melting point to about 1500 °C (2700 °F) in soda-lime glass. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.
Metals have various melting points depending upon the type. A few examples are listed below:
Melting Point Degrees are in both Celsius and Fahrenheit
Aluminum 659 C 1218 F
Brass 900-940 C 1652-1724 F
Gold 1063 C 1946 F
Silver 961 C 1762 F
Stainless Steel 1363 C 2550 F
Titanium 1795 C 3263 FTo go from Fahrenheit to Celsius:
That’s HOT!1. Begin by subtracting 32 from the Fahrenheit number.
2. Divide the answer by 9.
3. Then multiply that answer by 5.
Plastic is also a common material.
These parts are made with different lengths in order to fit a person’s face.
So Many Lengths to Measure! It is important that each of these measurements are correct to create the pair of glasses that best fits you. If a child wears glasses, these lengths will change as the child grows. As stated on the previous slide, these lengths are measured in mmMy own measurements are listed below:arm length= 115mmbridge width= 17.5mmlens depth= 27.5mm
Example +1.00 is one diopter of far sightedness.
Example -2.00 is two diopters of near sightedness
Diopter is the unit of measurement used to measure the concave or convex shape of the lens. This shape reflects light. More on diopters in the next slide!
human eye is about 40 diopters.
88 mm, and the viewing distance is 6 meters.
1 meter = 3.2808399 feet
6 meters = 19.6850394 ft
so on.” (Dr. August Colenbrander)
Geometry includes shapes and their corresponding angles. The next two slides will show display these angles.
Any shape with four sides including rectangles and squares
A four-sided polygon having all right angles. The sum of the angles of a rectangle is 360 degrees.
A four-sided polygon having equal-length sides meeting at right angles. The sum of the angles of a square is 360 degrees.
Some frames are triangular. There are two triangles in every square!
Shapes continued…OvalThe area of an oval is given by: Pi x 0.5a x 0.5b (Pi is the ratio of a circle's circumference divided by its diameter )Where a is the length of the longest side at its greatest width, and b is the length of the shortest side at its greatest height.CircleA circle's circumference or perimeter is the distance around the circle. The diameter is the line length from one point on the circle to the opposite point on the other side. The line goes through the center of the circle and ends on the circle.The Radius of a circle is the distance from the center of the circle to the outside edge.
SunglassesSunglasses areimportant for multiplereasons. They include1. uv protection2. glare protection3. eliminating certain frequencies of lightSunglasses can be made to block varyingpercentagesof uv light. You can get sunglassthat block 100% !
ConclusionIt is amazing that math can be related toso many things in the world. After all, it is logic and pattern. Thank you for learning a little about how math relates to eyeglasses-an object that many of us wear everyday!