No, you needn't take eye examination again. Commonly, There won't much changes of your prescription during two months. So, the prescription available for your vision requirements. But you shall remember to tell optician that you want computer glasses. If you plan to order prescription computer glasses online, you shall note your usages - to see computer after you input prescription.
Yes. You need to get another eye exam to get a special prescription for computer eye glasses. Even if you got your prescription 2months ago and your prescription is valid, you can't get your prescription computer glasses with your old prescription because the prescription for regular glasses is different from that for a computer. regular glasses are used to view distance while computer glasses are for mild distance. So Before you go to get prescription computer eyeglasses, you should have your eyes examed so that the computer glasses can fit you properly.
That depends on whether or not you already wear prescription eyeglasses. There are readily made computer glasses available in drug stores, but you can never pick them up easily without asking yourself if they are for you. Due to the fact that the vision range required for computer screen is about an arm's length, the focal length should be about 2/3 of the reading length. Presbyopia and myopia sufferers should get their glasses prescribed while healthy wearers needn't.