objective (ob-jek'tiv). 1

Of symptoms, revealed by physical examination, as opposed to those that are subjective. 2. A lens or combination of lenses in an optical instrument which is next the object and serves to form a real image of it. With the microscope and telescope this real image is then observed with an ocular. achromatic o. An o. of a microscope in which the lenses eliminate the color or chromatic aberration, dry o. An o. in which the space between the front lens and the object is filled with air. homogeneous immersion o. An o. in which the immersion fluid has the same refractive index as crown gla ; frequently designated as oil immersion o., as thickened cedar oil is the commonest homogeneous immersion fluid, immersion o. A microscope o. in which the space between the front lens and the object or the cover gla is filled with some liquid. [Lat, objecere, to throw before.]