What are the differences between optical microscopy and electron microscopy?

Basis of differentiation

Optical microscopy

Electron microscopy

Definition

A light or optical microscope is used to make small compounds visible through a magnified image (through glass lenses)

Is a microscope which uses accelerated beams of electrons (through electromagnetic lenses)

Magnification

Has lower magnification compared to an electron microscope (up to 1500X)

Has a high magnification compared to the light microscope (as high as 10,000,000 X) 

Samples visualized

Live and dead samples can be visualized

Only dead and dried samples can be seen

Radiation leakage

Has no risk of radiation leakage

Has a risk of radiation leakage

Resolution

Low resolution

High resolution

Illumination source

Light rays

Electron beams

Cost

Is cost-effective and low maintenance 

Is expensive and high maintenance

Sample preparation 

Sample preparation takes a few minutes to hours

Sample preparation takes several days to weeks

Method for viewing images

Images are viewed through the eyepiece

Images are visualized on the zinc sulfate or photographic plate fluorescent screen

Size

Light microscopes are comparatively smaller, and lighter than electron microscopes and easier to move

Electron microscopes are heavier and larger than light microscopes, and may weigh up to half a ton

Vacuum 

Does not require to be used in a vacuum

High vacuum is required to avoid scattering of the electron beams