"Bad eyesight" is a general term, and a "bad" eyesight measurement depends on the specific eye condition and the intended use.
Here are some examples of what might be considered a "bad" eyesight measurement:
- High refractive error: This refers to a significant difference between how light focuses on the retina and how it should. High refractive errors can include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (blurred vision at all distances).
- Vision loss: This refers to a decrease in visual acuity, which is the sharpness of vision. Vision loss can be caused by various factors, including glaucoma, macular degeneration, and diabetic retinopathy.
- Eye muscle imbalance: This refers to a misalignment of the eyes, which can cause double vision or strabismus.
- Visual field defects: This refers to a loss of peripheral vision, which can be caused by various conditions, including glaucoma and stroke.
What's considered "bad" can vary based on the individual's needs and lifestyle:
- For driving: A person with 20/40 vision may be considered legally blind for driving, while someone with 20/20 vision might be considered "good."
- For reading: A person with 20/20 vision might have difficulty reading small print, while someone with 20/15 vision might have no problem.
- For sports: A person with 20/20 vision might struggle to see a fast-moving ball, while someone with 20/10 vision might have an advantage.
Ultimately, what constitutes "bad" eyesight is subjective and depends on the individual's needs and lifestyle. It's important to consult an eye doctor for a comprehensive eye exam to determine the best course of action.
