Q: How bad do your eyes have to be for LASIK to work? How bad do your eyes have to be for LASIK not to work (as well)? A:  Lasik is recommended for people who have bad enough vision to benefit from wearing glasses or contact lenses. Andrew Caster, MD

Q: Since the cost of glasses are $500.00 my husband said I should consider lasik. Does my eye sight have to be stable to be a candidate? I'm 54 years old and both my reading and distance vision worsen every year. A: Lasik will not stop the eyes from changing. We would expect your near vision to change at this age, as you are developing the middle age "presbyopia". That should not stop you from having the procedure. But if your distance vison is changing substantially every year, then you may want to wait. It would be very unusual for someone your age to have the distance vision changing substantially. Andrew Caster, MD

Q: Hello, I am 39 years old and interested in Lasik surgery. I have worn corrective lenses since I was 2. Based on my astigmitism and prescription, I was wondering if you thought I would be a good canidate for the proceedure? Left eye: BC 8.5, SPH -5.75, CYL -2.75, AX 160 Right eye: BC 8.5, SPH -6.00, CYL -2.75, AX 20 Thank You A: Most people with your prescription are good candidates for laser vision correction. I suggest that you obtain a personal consultation. Andrew Caster, MD

Q: Nine days ago I had wavefront LASIK enhancement for small amounts of myopia and astigmatism in one eye. I think my eye is overcorrected. Is it possible my eye might regress to better vision in the next month? I haven't seen any change in the past four days. A: Most likely, the vision will improve significantly over the next month or two. If not, a further enhancement may be needed. Andrew Caster, MD

Q: How do I go from wearing RGP lenses to a LASIK procedure. I have been wearing RGP lenses for about 22 years. A: You must allow time for your eyes to revert back to their normal shape, which can be temporarily distorted by wearing RGP contacts. This can often take several months. Andrew Caster, MD

Q: I have very large pupils and am considerably nearsighted (-3.75, no astigmatism). I have always been advised against surgury in the past, but, it's been a couple of years since I've seen anyone. It seems there are some options that may be available to me now. I have an eye appointment coming up and I will get my pupils measured at that point. What would be a reasonable cut off to consider surgery? If I meet the cut-off, what are my best options to research in the San Diego area? Thanks, Andrea A: There is considerable controversy about the role of large pupils in causing glare and halos, with some studies showing no effect at all, while others feel that people with large pupils are more likely to get bothersome glare or halos after surgery. If pupils do have an effect, it is most likely the combination of large pupils and a very large correction. I would characterize your correction as medium. There are no hard and fast cutoffs. Andrew Caster, MD

Q:  Hi, I am 42 and have had myopia pretty much all my life. My prescription is -7.0 and -7.5 and has been steady for the last 20 or so years. I also have astigmatism in one (or both eyes) and I currently wear glasses. I had an eye examination in New Zealand last June and was told my cornea flaps (?) were thick enough, that I was eligible for laser Lasik but that I wouldn't achieve 20/20. There was a slight problem the doctor said, I can't remember the name she gave it but she demonstrated the problem by holding up a pair of black 'glasses' made of paper which had tiny tiny holes in them shaped like a cross. With these I could see the letters on the board much better. Please could you explain the 'problem' to me and how it would affect the results of Lasik surgery. And if, indeed, you think Lasik is for me. Thank you Very Much Ellie W. A: I need more information than what you have provided. I would recommend that you see another doctor to get a second opinion. Andrew Caster, MD

Q:  Dear Dr Caster, I do not currently have my glasses prescription but I do have my contact lense one and it says: left eye BC 8.7 power -4.75 cyl -2.25 axis 110, right eye BC 8.7 power -5.25 cyl -2.25 axis 050. However when I am wearing them, or glasses, I am only able to see the first 6 lines in the wall charts at the optician's (in the UK). I will be 18 in march and was looking for an impartial opinion on how effective lasik would be for me (How well would I be able to see after the treatment) and how old I would need to be before being able to undertake the treatment. A: Your prescription is good for laser vision correction, but the other measurements of the eye must be within the proper bounds. People in their teenage years sometimes are still growing and their prescriptions can still sometimes be changing, so you should wait until you have two years with a total of less than a 0.5 diopter change (that would be in the first two numbers for each eye). Andrew Caster, MD

Q: I had PRK surgery on my left eye 11 days ago. My vision is still a bit foggy. Is this normal? A: PRK takes longer to heal than Lasik, and it is expected that the vision would be a bit foggy 11 days after the procedure. Andrew Caster, MD www.CasterVision.com

Q:  I had an eye injury when I was 4 years old; the corner of a 3/4" sheet of steel entered my eye. I now have scar tissue on my retna, a slightly deformed iris (due to entry), and 20/80 vision in that eye (right). In four years, I will be entering a career in which my eye sight may not be worst than 20/60 and must be able to be corrected to 20/20. Is there any way I can use these four years to my advantage? Do you have any advise on how I may correct my vision to suit my chosen career? A: You need to be evaluated in person by a lasik specialist. Andrew Caster, MD www.CasterVision.com