How your eyes work
Firstly we’re looking to see how well your eyes work at a distance. We look to see how well they work on their own without any help and we also look to see how well they can work at their best with whatever glasses or contact lenses are required. Obviously to do that we have to find out what glasses or contact lenses give you the very best vision and this forms the basis of your spectacle or contact lens prescription.
We then look to see how well the two eyes work together and determine whether there is any improvement that can be made to your spectacle prescription to help them work together better. This might be a small change in the overall strength of one or both lenses or it might be some prism built into your spectacle lenses.
Then we look to see how well the eyes work at your normal reading distance – and sometimes your normal distance for viewing a computer screen. The difference between your distance prescription and your near prescription, usually referred to as the ‘Add’, is dependent mostly on your age and on the actual distance at which you habitually read.
Having worked out what prescription you need to achieve your very best vision, we can then see whether the standard of vision you get, at your very best, is what we would expect for the things we know about you. If it isn’t then we have more reason to look very closely at what is happening to your eyes that has made the vision deteriorate.
In the next blog I will discuss how we look at the various structures in the eye.