Os: 0.5x-0.5, od: 0x-0.25 after lasik. right eye always strained after reading. is this presbyopia, or result of different refraction? disappointed!

Presbyopia normal: This is normal. As we get older we gradually lose our ability to focus on things closer to us. Our "near vision"- this loss is called presbyopia. It is corrected by adding a "close up" refraction to your glasses- for reading called "an add." lasik doesn't correct this.

Presbyopia: Those numbers are consistent with near perfect distance correction in the right eye, and slight nearsightedness in the left. The better the distance vision the harder it is to see close because of presbyopia. If all else is normal, your right eye should have slightly better distance vision far and you left slightly better close. Unfortunately reading will get worse with age.

Both: Depends on your goals prior to lasik surgery as your presbyopia can be accounted for with planned blend vision/monovision/presbylasik preoperative simulation sometimes avoids such disappointment. This can still be corrected. Ask your surgeon.