I/O errors usually indicate errors with the hardware. There isn't really much you can do here except replace the drive.
The only fix you should try before you replace the drive is the UpperFilters and LowerFilters registry fix. Although it does not directly relate to your problem, give it a shot.
1. Navigate to registry key: HKEY_LOCAL_MACHINE/SYSTEM/CURRENTCONTROLSET/CONTROL/CLASS/{4D36E965-E325-11CE-BFC1-08002BE10318}
2. Delete UpperFilters and LowerFilters Keys
3. Reboot
-------------------------- (ONLY IF NECESSARY, PROCEED)
1. Right click on Computer and click Manage.
2. Select Disk Management.
3. Right click on the DVD drive that isn't working and change the drive letter.
4. If changing the letter makes it appear, change it back.