Most of your questions cannot be answered because they are too general. It's like asking "I'm going on a trip, what can happen to me?" 1 Most, but not all patients with high myopia live their lives without complication. But can't tell you what will happen. 2. Same answer, varies with individual. Some stop at -5, some keep going at -12. 3. While there is some variation most doctors us greater than -6 for high myopia. Pathological is added when complications like macular degeneration, retinal holes/tear/detachment. Again can't generalize, one person my have myopic macular degeneartion with -6 and another person none with -25. In general the larger the number the greater the risk. 4. the problem with pathological myopia is the eye is too long. Refractive surgery, clear lens replacement and intraocular contact lens don't make the eye shorter or reduce complications, only provide a way of correctiing vision other than very thick glasses.