MICROANATOMY

Detailed explanation-1: -Without the oil the light rays are refracted as they enter the air between the slide and the lens and the objective lens would have to be increased in diameter in order to capture them. Using oil has the same effect as increasing the objective diameter therefore improving the resolving power of the lens.

Detailed explanation-2: -Immersion oil is used for viewing specimens with 100x objectives to help create a pathway for light. Light travels differently through air versus glass. As you increase the magnification, this distortion becomes more noticeable. The immersion oil helps bridge the gap between the microscope slide and the objective.

Detailed explanation-3: -To have good resolution at 1000x, you will need a relatively sophisticated microscope with an Abbe condenser. An Abbe condenser is composed of two lenses that control the light that passes through the specimen before entering the objective lens on the microscope.