Transcript
VISION ACUITY – JAEGER READING CARD EXAMINATION
For near vision, 14/14 (35/35) is normal, with 14 in. (36 cm) being the normal distance for reading. If the second number is greater than 14 (14/20, for example, or 35/50), it means that you have reduced near vision. You have to be 14 in. (36 cm) away to read print that people with normal near vision can read from 20 in. (51 cm). A Jaeger (J) number is another way to rate near vision. The J number relates to the size of text you could read on the Jaeger chart. The J number goes up as the print size of the text you read goes up. The higher the J number, the worse near vision. The number can range from J1 to J16. For example:
J 1 m e a n s t h a t y o u c o u l d r e a d t h e s m a l l e s t t ex ex t o n t h e c h a r t a n d t h a t y o u h a v e 2 0 /1 /1 5 v i s i o n .
J 2 m e a n s t h e l i n e o f t e x t y o u w e r e a b l e t o r e a d h a d l a r g e r p r i n t t h a n J 1 , a n d y o u r v i s i o n i s 2 0 /2 /2 0 .
J3 means the line of text you were able to read had larger print than J1 and J2, and your your vision is is 20/40. Visual acuity tests usually take about 5 to 10 minutes. Refraction
The health professional tests your eyes with different lenses until the lens that corrects your vision the best (sometimes better than 20/20 or 6/6) is found. The result of a refraction test determines your prescription eyeglass or contact lens strength. A refraction test takes 5 to 30 minutes (30 minutes if dilating drops are used). Visual field test
Normally, a person's visual field forms a rough circle with a natural blind spot. If your vision is normal, you should be able to see objects clearly throughout the entire visual field except for the area with the natural blind spot. When you are using both eyes to see, the blind spots do not interfere with your vision. You may have vision loss in certain areas of the visual field if you are not able to see:
Test objects during tangent screen testing. Movements or light flashes during perimetry testing. Abnormal results during Amsler grid testing include:
Not being able to see the black dot at the center of the grid. grid. Not being able to see all four edges of the grid. Having blank spots or dark dark spots on the grid (other than the black dot at at the center). Seeing lines that look wavy or curved. Gaps in different parts of the visual field may have many causes, including eye diseases (such as glaucoma and macular degeneration) or nervous system problems (such as stroke). If results on any of the visual field tests are abnormal, you will need further tests to determine the cause.
