India, July 19 -- Your spectacle prescription is unlikely to remain the same for life. Headaches, squinting and holding your phone farther away could signal that your spectacle prescription has changed. An ophthalmologist explains when vision is most likely to change and the signs to watch for. "The earlier window (of power change) falls across childhood and the teenage years, a period when the eyes are still actively developing and growing," says Dr Ankit Vinayak, a Gurugram-based consultant ophthalmologist. "Then, somewhere around the fourth decade of life, a second shift quietly takes hold as presbyopia emerges, gradually stealing the ability to see nearby objects with clarity," he adds. Dr Vinayak says regular eye examinations should not be skipped, as uncorrected vision can affect children's academic performance, adults' productivity and cause eye strain. Eye tests can also detect diseases early. He recommends routine eye examinations for children and adults over 40, even without noticeable vision changes....