Convert the following prescriptions to + or - cylinder notation and state the type of 
astigmatism which is present in each

a. +4.00 / -1.50 x 70

b. +1.25 / -3.00 x 90

c. PL / +1.50 x 45

d. -2.00 / +2.00 x 50

e. - 1.75 / -2.00 x 135