Our eye forum will be able to help you, good luck.
20/20 means you can see at 20 feet what a normal eye should see at 20 feet
mildly farsighted and has a significant amount of astigmatism.
The +1.75 value is the sphere correction for farsightedness. The -2.75 value is the cylinder power of correction for astigmatism. The x170 and x005 values indicate the axis of astigmatism for the right and left eyes respectively. Astigmatism is a deviation from rotational symmetry in the focusing power of the eye. It is usually caused by an irregularly shaped cornea.
You can get an approximate idea of what her uncorrected vision is like by using this link:
http://www.optiker.at/simulator/
This is an eyesight simulator. Just key in the numbers under 'cyl' and 'sph'. It helps if you can read German but it isn't essential. 'Alter' means 'age' by the way