text: can anyone tell me what my glasses prescription means? i went to the optician today and i need to get some glasses. i have some basic knowledge about ophthalmology as i'm about to be a doctor, so i know the basics about how light focuses on the eye etc etc. and i understand the basic concept of astigmatism and how the eye is shaped more lke a rugby ball than a football....  anyway, my prescription from the optician is:  r: sph -1.00  cyl -0.50   axis 115 l:  sph -1.25  cyl - 0.50  axis  90  i understand that it shows myopia in both eyes, left slightly worse than right, but what do the other numbers mean? it's something to do with the degree of astigmatism, but what do they actually show? and what does that mean in terms of my eyes?  just interested!!! sph = sphere  the amount of long or short sightedness. it always has a plus (+) or a minus (-) sign in front or above it. if the vision in one eye is very poor, the word 'balance' or 'bal' may be written.  for example, i'm -3.00 in both right and left. so baisically, it tells you how blind you are  cyl = cylinder (astigmatism) this is the measure for astigmatism. again, there is always a plus (+) or minus (-) sign present  axis - this will only appear if there is a value for cylinder, as it relates to the cylindrical lens. it will be a number between 1 and 180. it may or may not be written with a degree 'o' symbol after the number.    hope this helps