Firstly let me say that the vast majority of people we see have absolutely
nothing more wrong with their eyes than some kind of focussing error.
The image on the left shows a perfectly normal eye.
(click to enlarge)
Some of the eye conditions we routinely look out for are:
Glaucoma is a condition where the pressure inside the eye becomes too
great and begins to damage the delicate nerve structures which if left
untreated can lead eventually to tunnel vision.
We perform 3 tests to check for this:
2. Optic nerve head
3 Visual fields
Diabetes can affect vision if it isn't monitored carefully, with this
in mind all diabetics are now given an annual check at the hospital to
look for weakness in the retinal vessels.
Think of what happens when you boil an egg, the white swells (punch a
hole in the shell and watch it pluther out all over the place) then goes
from clear to opaque. The same effect happens in older eyes but much
more slowly, early cataracts often start with the eye becoming more
short sighted as the lens swells.
distance vision blurs but near vision stays good then as the cataract
develops the overall vision gradually blurs.
These day's cataract removal is a very simple procedure
This is too big a subject for me to cover here but these sites:
contain a wealth of information for further reading