Periodic tables

Past 

In the past I knew about how it had metals and non metals. I also knew it was catagorized by atomic number. I even knew that hydrogen is the first element. Lastly I knew that it has 9 rows and 18 columns. 

Present

I know everything I used to know. I know now that Mendeleev invented it. I also know that 90 elements occur in nature. Lastly I know that technetium was the first man made element. 

Future 

I want to learn more about Mendeleev. I also want to learn about how he made it. I even want to know how scientists make new elements. Lastly I want to learn more about all the individual elements. 

http://en.m.wikipedia.org/wiki/Periodic_table

Vision

20/20 Vison

Sharpness of objects at 20 ft

Vison Tests

An eye chart 

Correction Options 

Eyeglasses

What it is 

Oldest form of vision correction 

Practical and afordable 

How it works 

Bends the light coming into the eye 

Uses concave and convex lenses 

Concave for nearsightedness 

Convex for farsightedness

Contact Lenses 

What is it 

Better for active people 

Sit on your eye 

Can wear sunglasses with them 

Different brands, colors, and materials 

How it works 

They are directly on your eye so they can be thinner

Corrective surgery 

What is it 

Changes refractive (light bending) properties of the eyes 

The surgery is not cosmetic it is functional 

No dependence on glasses or contacts 

How it works 

Surgeon cuts a flap in the cornea 

Opens up the flap 

Uses a laser to put in a unique corrective pattern 

Citation: 

Kozarsky, A (2014) Eye Health and Vision Basics [web] retrieved from; http://www.webmd.com/eye-health/vision-basics Date accessed: January 6, 2015