P3 - Correcting Vision Flashcards Preview

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Flashcards in P3 - Correcting Vision Deck (10)
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1
Q

How do you correct short sight?

A

Using a diverging lens.

2
Q

What is wrong with short sight?

A

The image focuses in front of the retina.

3
Q

Who are more likely to be long sighted and why?

A

Young children - their lenses grow quicker than the eyeballs.

4
Q

What is long sight caused by?

A

The eyeball being too short or the cornea and lens being too weak.

5
Q

What lens is used to correct long sight?

A

Converging lens.

6
Q

What is a laser?

A

A narrow, intense beam of light with waves of equal wavelength.

7
Q

Lasers cauterise - what does this mean and how does it help? [1-2]

A

They burn and seal small blood vessels to reduce the amount of blood lost and protects against infection.

8
Q

How can lasers be used to treat skin conditions?

A

They burn off the top scarred layer to reveal less-scarred lower layers.

9
Q

How does laser eye surgery work?

A

The laser vaporises the cornea to alter its shape and focusing ability.

10
Q

What is short sight caused by? [2]

A

The eyeball being too long or the cornea and lens system being too powerful.