I've read that most people seem to have their myopia stop progressing by their early twenties, some continue to see it progress into mid and even late twenties. Different MDs at the American Academy of Ophthalmology posted:
http://www.aao.org/eye-health/ask-ophthalmologist-q/high-myopia
"In this condition the growth of the eye will generally stabilize between 20 to 30 years of age. "
http://www.aao.org/eye-health/diseases/myopia-nearsightedness
"High myopia will usually stabilize between the ages of 20-30 years old. "
A 25 yr old high myope had asked about worsening myopia and gotten this response:
http://www.aao.org/eye-health/ask-ophthalmologist-q/should-i-be-concerned-about-my-high-myopia
"At your age having as little as .5D of change is normal. I would advise ICL (implantable contact lens) as this would leave your cornea untouched. Thus, if you needed a bit more treatment as you age, you could easily have a small amount of LASIK/PRK performed to sharpen up your vision. "
A study of myopia progression in adult contact lens wearers age 20-40 showed that even after that a minority see some progression in their myopia:
http://iovs.arvojournals.org/article.aspx?articleid=2123890
"Of these, 21.3% progressed by at least −1.00 D over the 5-year period. The 5-year rate of progression decreased with increasing age...
. Table 1 shows that the frequency of myopia progression decreases with age from 34.9% in 20 to 25 year olds to 10.0% in 35 to 40 year olds ...
Studies of students and military recruits in their twenties suggest that between 26% and 47% of myopes progress by at least −0.50 D over a period of up to 3 years. 3 4 6 Data on older subjects are scarce, but Ellingsen et al. 8 found a mean shift of −0.39 D per decade in myopes in their thirties "
First its not possible to tell when anyone's glasses RX (prescription) will stop changing. second there is no reason to believe you will be blind by 30. It's not your vision without glasses that is important its what you see with glasses or contacts. Finally I would see a MINIMUM OF THREE different refractive-lasik surgeons to learn your options on refractive surgery: lasik, PRK (surface surgery) and ICL and clear lens extraction. (the latter two are much higher risk and much more controversial)