are my spectacle prescriptions similar?

Question

i have a prescription from 1999 which is right: sph +1.25 cyl -2.50 axis 5 left sph +0.50 cyl -2.25 axis 170 however a prescription from this year is as follows right sph -0.75 cyl-1.00 axis 5 left -0.75 cyl -0.50 axis 175 as you can can see there are different measures but would it be correct to wok the sum out of the cyl and sph to establish the power of correction?

i do not have cataracts, i am 27 years old

p.s i am looking to have lasik carried out but i do not have a prescrption between 2002 and may this year so i cannot prove stability in my prescription for the required previous year, i was hoping my prescrition had been consistent from 1999 and 2002(the prescription of which is in the post to me)

Answer 1

They are not similar. In 1999 you were hyperopic with significant astigmatism, now you are myopic with mild astigatism. Are you an older person developing cataract?, that kind of change is not unusual when developing cataract

Not sure what you mean by "sum" and "power of correction". You can calculate equivalent sphere power.

equivalent sphere
1999 :
R: plano
L: -0.50

now:
R: -1.25
L: -1.00

Answer 2

no. those are not all that similar. one is "mixed" astigmatism and the other is "compound myopic" astigmatism. pretty big difference.