Eyewear Shelf

Online Eyewear Shops Compared: Prescription Range, Lens Index, and Return Policy

2026.07.03

This reference page provides a comparative overview of leading online eyewear and contact lens retailers. It focuses on technical specifications including available prescription ranges, lens index options for varying vision needs, and consumer return policies as of 2026.

Comparison of Online Eyewear Shops

The following table compares major online retailers based on their technical capabilities and consumer protections. Prescription ranges refer to single-vision lenses unless otherwise noted.

Retailer Prescription Range (SPH/CYL) Available Lens Indices Return Policy
Zenni Optical SPH: -20.00 to +12.00; CYL: ±6.00 [1] 1.50, 1.57, 1.61, 1.67, 1.74 14 days for refund; 30 days for store credit [2]
EyeBuyDirect SPH: Up to ±9.25+; CYL: ±4.25 to ±6.00 [3] 1.50, 1.57, 1.59, 1.60, 1.67, 1.74 14-day "Fit & Style" guarantee; 365-day product warranty [4]
Warby Parker Standard to High (1.74 index recommended for ±8.00+) [5] 1.50 (Polycarbonate), 1.67, 1.74 30 days for refund or exchange [6]
GlassesUSA SPH: -14.00 to +9.00 [7] 1.50, 1.61, 1.67, 1.74 45-day risk-free return policy [8]
Coastal / Clearly SPH: -20.00 to +12.00; CYL: ±6.00 [9] 1.50, 1.59, 1.67 30 to 60 days depending on region/brand [10]
Zeelool SPH: -20.00 to +12.00 [11] 1.50, 1.56, 1.61, 1.67, 1.74 30 days for exchange or refund [12]
Firmoo SPH: -18.00 to +10.00; CYL: ±4.50 [13] 1.50, 1.56, 1.60, 1.67, 1.74 30 to 60 days for exchange or refund [14]
Vooglam SPH: ±9.25+; CYL: ±4.25 to ±6.00 [15] 1.50, 1.57, 1.61, 1.67, 1.71, 1.74 30 days for exchange or refund [16]
LensCrafters (Online) SPH: -14.00 to +8.00 [17] 1.50, 1.59, 1.67, 1.74 30 days for refund or replacement [18]
Target Optical (Online) Standard Luxottica Range (similar to LensCrafters) 1.50, 1.59, 1.67, 1.74 90-day "unconditional" happiness guarantee [19]

Technical Definitions and Lens Indices

Sphere (SPH)
The primary power of the lens, measured in diopters. Negative values indicate nearsightedness (myopia), while positive values indicate farsightedness (hyperopia).
Cylinder (CYL)
The lens power required to correct astigmatism. If this field is blank, the eye is spherical and does not require astigmatism correction.
Lens Index (Refractive Index)
A numerical value representing how efficiently a material bends light. Higher indices allow for thinner lenses in stronger prescriptions.
1.50 Index (Standard)
Conventional plastic (CR-39) lenses. Best suited for weak prescriptions between SPH -3.00 and +3.00.
1.57 - 1.61 Index (Mid to High)
Thinner than standard plastic. Recommended for moderate prescriptions to reduce edge thickness and weight.
1.67 Index (High Index)
Significantly thinner and lighter. Typically recommended for prescriptions above +/- 4.00 diopters.
1.74 Index (Ultra High Index)
The thinnest plastic lens material available. Recommended for very strong prescriptions (typically +/- 8.00 diopters or higher) to minimize the "coke bottle" effect.
Polycarbonate (1.59 Index)
A highly impact-resistant material often used for sports eyewear and children's glasses. It is thinner than 1.50 plastic but has lower optical clarity (Abbe value).
Trivex (1.53 Index)
A lightweight, impact-resistant material that offers superior optical clarity compared to polycarbonate.
Prism Correction
Used to treat eye alignment issues or double vision. Many online retailers have strict limits on prism (often up to 5.00 diopters) or do not offer it online due to the need for precise physical measurements.

Last verified: 2026-07-03

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