Summarize the following:
If you are experiencing the symptoms above you shouldn't waste time before booking an appointment with your eye doctor for a test. You can also, however, do some basic tests at home to try to measure your sight. Try by printing out the classic test page with letters of diminishing size from the internet.  After printing the test sheet, hang it at eye level in a well lit room. Stand ten-feet back and see how many letters you can read. Continue right to the bottom row, or as low as you can go, and write the number of the line where you could read most of the letters. Do this again, covering each eye at a time. The results vary by age, but older children and adults should be able to read the majority of the 20/20 line at the bottom. As well as printable test sheets, there are a number of tests that you can do directly on your computer. Again, these are not exactly perfect, but they can give you a basic indication of how your eyes are. You can find different tests for different eye problems, including colour blindness, and astigmatism.  They will involve you looking at different images and shapes on your computer screen, and following the instructions to test your eyes. Remember that these are vague guides, and should not be treated as a substitute for the real thing. Don't forget that if you are experiencing these symptoms you need to make an appointment with your eye specialist and have a full eye exam. Your optometrist or ophthalmologist will conduct a number of tests that will get to the bottom of your eye problems, and if you need glasses they will write you out a prescription. It might be intimidating or a little scary at first, but it's essential to caring for your eyes.  The eye doctor may use a number of instruments, aim bright lights into your eye, and have you try out a number of different lenses.  You will have to read out letters from a test sheet with while different lenses are held in front of your eyes. Ophthalmologists and optometrists are both qualified to conduct eye evaluations. After your eye exam you will be told if you need glasses or not. If so, you will be provided with a prescription. You can then take this to any optician's and choose which frames you want to get. Opticians are trained to help fit people for glasses. Once you have chosen your frames you will have to wait a week or two for the frames to be fitted before you can pick them up.

Summary:
Use some testing printouts. Try some online tests. Go to see your eye doctor. Know the next steps if you need glasses.