My earlier eye number was -0.75 and -0.5 I used glasses with that number for 5 years. Recently I have made new glasses as my eye number has changed to -1.75 and -1.25 My far sight vision has become very clear now but while reading my eyes strain i have alot of paper work to do , the vision is clear but feels like some strech and starin is there ..is this because i have changed my glases aftr 5 years and how many days will it take to be normal.