The highest category of bad eyesight, as defined by the provided reference, is Extreme, which corresponds to a prescription measurement greater than -10.
Understanding the severity of bad eyesight often relies on the diopter measurement of a prescription lens needed to correct vision. A negative number indicates myopia (nearsightedness), and a larger negative number signifies more severe vision impairment.
According to the information provided:
| Category | Diopter Measurement |
|---|---|
| Mild | -0.50 to -3.00 |
| Moderate | -3.25 to -5.00 |
| High | -5.25 to -10.00 |
| Extreme | greater than -10 |
The term "greater than -10" in this context means any number that is more negative than -10, such as -10.25, -11.00, -15.50, or even -20.00. These increasingly negative numbers indicate a higher degree of myopia, requiring stronger lenses for correction. Therefore, the Extreme category represents the most severe level of bad eyesight listed.
For example:
- Someone with a prescription of -2.50 has mild bad eyesight.
- Someone with a prescription of -7.00 has high bad eyesight.
- Someone with a prescription of -12.00 has extreme bad eyesight, falling into the highest category.
This categorization helps eye care professionals describe and classify the severity of myopia, guiding treatment and management plans.
