Is 4.5 Eyesight Bad?
Yes, an eyesight measurement of ±4.5 is considered relatively bad compared to someone with a prescription closer to ±1.00.
Eyeglass prescriptions use diopters (D) to measure the refractive power needed to correct vision. A diopter measures the strength of the lens required to focus light correctly onto the retina.
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Lower Diopters (e.g., ±1.00): Indicate a smaller refractive error, meaning less correction is needed. This generally suggests better eyesight. As stated in several sources (Heffington's, Reddit), a diopter range of ±1.00 to ±3.00 is considered mild to moderate.
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Higher Diopters (e.g., ±4.50): Indicate a larger refractive error, requiring stronger corrective lenses. This implies a greater degree of nearsightedness (for negative values) or farsightedness (for positive values). Sources like Heffington's and Quora highlight that ±4.50 represents a significant need for correction. All About Vision categorizes -2.25 to -5.00 as moderate to high nearsightedness.
Severity of ±4.5 Diopters
A prescription of -4.5 indicates moderate to high nearsightedness (Quora), meaning you struggle to see distant objects clearly. A prescription of +4.5 would indicate a similar level of farsightedness, making it difficult to see near objects clearly. While not extreme, it still signifies a substantial visual impairment requiring significant correction.
