Dispensing 1

What is the material been used in manufacturing lens before century?

• Stone

• Glass

• Mirror

• water

Choose the common shape of the ophthalmic lens in 13^th century.

• Triangle

• Square

• Round

• Dome

In which year the ophthalmic lens with rim was invented?

• In 1750

• In 1990

• In 13th Centiry

• Before 10th century

Astigmatic ophthalmic lens was invented by __________.

• W. cary
• Monoyer

• Dr Tscherning

• Allvar Gulstrand

Bifocal lens was invented in _____.

• 1888

• 1908

• 1926

• 1955

Which country the CR39 material was developed?

• Canada

• Colombo

• Colombia

• Costa Rica

Which of the following statement is BEST described the plastic lens?

• Plastic lens is the most common materials for safety lens

• plastic lens has scratch resistant surface

• Plastic Lens is the most ecomomical lens

• Plastic lens has index of 1.53

What is the highest possible index of refraction used in plastic ophthalmic lenses?

• 1.80

• 1.50

• 1.61

• 1.74

Which of the following statement is BEST described the ophthalmic lens hand neutralization?

• The most accurate method to measure the lens power

• it can be used to measure the amount of prism in the lens

• It is used to measure the front vertex power of the lens

• It can be used to locate the optical centre of the lens

Focimeter is the instrument that measures the _________ and _________ of a lens.

• power, curvature

• power, optical center

• optical centre, thickness

• curvature, optical centre