Power Pattern - Box4d

power 4dAnyway coming to your question the requirement of +- 4D for a job means that the eyesht of an applicant should not exceed these values that is +4D and -4D and in otherAnswer:the power of a convex lens is always positive. as you can see here the power is +4D, therefore the nature of the lens is that it is a convex lens. we know, P = 1f. also