Probably you have a pension plan, being a teacher. The pension and OAS should provide you with enough income to cover the cost of long-term care when you'll get one of the aging illnesses.
Probably you should plan doing all the active living before the age 80. The quality of life usually starts to decline after that and probably the pension/OAS will cover your needs after that.
Lets assume you are now 45 and will retire in 10 years at 55. Your investments will need to cover 25 years. Let's assume you will need to spend $100,000/year (you need to actually compute how much you'll need). Apply the present value formula to determine how much money you need at 55 so that the future value in 25 years is $0 (the simplest way to do this is with a spreadsheet). The result is $1,067,477. If you already have more than that, you are good, no other saving is required and you can start spending all your paychecks and also consider increasing the standard of living beyond $100,000/year. If you don't have that, you need to compute how much do you need to save over the next 10 years (before retirement) to achieve that. Again you can use the future value formula. For example, if you already have saved $400,000, you'll need to save an additional $14,075/year to reach the above mentioned goal.
The rate of return used was 8%, which is the expected return anyone can get with minimal risks from a diversified portfolio in the long run. Inflation was not considered, so to be able to actually spend $100,000 after inflation your rate of return will have to be about 10% (or you'll need more investments).
I also have assumed that no effective aging cure will be developed in the next 35 years. If you think that aging may be cured during your lifetime, or that the healthy life span will become longer that the current 75, then you'll need to adjust the number of years you need your savings to last. The best bet in that case will be to have the spending covered only by investments' return (adjusted for inflation). For example, to spend $100,000/year adjusted for an inflation of 2%/year, you'll need investments of $2,011,340 at 8% return.