Yes, you need eyeglasses if you have double vision within up to 20 feet away.
It means that a person needs to be within 20 feet to clearly see what someone with "normal" (20/20) perfect vision can clearly see at 25 feet. It's good but not perfect vision
Normal vision as you can 16 feet of 16 feet.
which of the following indicates normal vision at 20 feet
It means seeing at 20 feet what a person with normal vision sees at 20 feet. A person who has 20/40 vision can see at 20 feet what the person with normal vision sees at 40 feet, etc. Some people have better than 20/20 vision.
To the general public, 20/20 vision means that you can see at 20 feet what an average person should be able to see at 20 feet. If you had 20/100 vision, it would mean you would have to be 20 feet away from something to see it whereas other people would generally be able to see that same object from 100 feet away. You would have VERY POOR vision. If you had 20/5 vision, it would mean you would see from 20 feet away those objects which people would generally have to be within 5 feet of to see clearly. You would have EXCEPTIONALLY GOOD vision. So the numerator (top number) is how far away YOU are standing to see clearly. The denominator (bottom number) is how far away the AVERAGE PERSON would need to stand to see clearly.
20/10 vision refers to vision better than 20/20. A person having 20/10 vision would be able to see something at 20 feet that a person with 20/20 vision would see at 10 feet.
Having 20/15 vision means the person can see at 20 feet what an average person can see at 15 feet, indicating better than average vision. In comparison, someone with 20/20 vision sees at 20 feet what an average person sees at 20 feet.
All 2015 means is that a person with 2015 vision can clearly see somthing 20 feet away that most people would need to be no more than 15 feet from. To this end, it is better. A person with 20/100 vision can see something 20 feet away that most people could normally see 100 feet away. --Yes, 20/15 is better vision than 20/20.
Normal vision is 20/20 vision, or in metric 6/6. This means that when you are 20 feet away from something, you will see what someone with normal vision would see at 20 feet away. With 20/40 vision, you would see something 20 feet away as someone with normal vision would see it at 40 feet, so therefore it would be blurry. 20/100 is also possible and 20/200 is considered legal blindness. 20/10 would be better than normal. (Adapted from howstuffworks.com)
20/20
20/200 means you can only see at 20 feet what a person with normal vision can see at 200 feet. Therefore you would be legally blind.
Franny's Feet - 2003 Happy Halloween Tunnel Vision was released on: USA: 19 October 2005