Soft contact lenses that have been prescribed by eye care practitioners are sometimes substituted for alternative lenses by unqualified, unregulated and sometimes even fully regulated lens suppliers, in the mistaken belief that there is essentially no difference between different soft lens types. This review considers the implications of inappropriately substituting soft contact lens types in terms of (a) lens properties: surface treatment, internal wetting agents, material, total diameter, back optic zone radius, thickness, edge profile, back surface design, optical design, power, colour (tint) and ultraviolet protection; and (b) lens usage: wearing modality (daily versus overnight wear) and replacement frequency. Potential aspects of patient dissatisfaction and adverse events when prescribed soft lenses are substituted for lenses with different properties or intended usage are considered. Substitution of 15 of the 16 lens properties considered (i.e. except for back surface design) was found to be related to at least one – and as many as six – potential sources of patient dissatisfaction and adverse ocular events. Contact lens are medical devices which are prescribed and fitted; they should never be substituted for another lens type in the absence of a new prescription further to a full finalised fitting, for the simple reason that all soft contact lenses are not created equal. A substituted lens may have properties that results in undesirable consequences in respect of vision, ocular health, comfort and cosmetic appearance, and may be incompatible with the lifestyle of the patient.

眼保健医生开具的软性隐形眼镜有时会被不合格、不受监管、有时甚至是完全受监管的镜片供应商替代，他们错误地认为不同软性镜片类型之间基本上没有区别。这篇综述考虑了在 (a) 镜片特性方面不当替换软性隐形眼镜类型的影响：表面处理、内部润湿剂、材料、总直径、后视区半径、厚度、边缘轮廓、后表面设计、光学设计、功率、颜色（色调）和紫外线防护；(b) 镜片使用：佩戴方式（每天佩戴与过夜佩戴）和更换频率。考虑到用规定的软性镜片代替具有不同特性或预期用途的镜片时患者不满意和不良事件的潜在方面。在所考虑的 16 种镜片特性中，有 15 种的替代物（即除了背面设计）被发现与至少一种（最多六种）患者不满意和不良眼部事件的潜在来源有关。隐形眼镜是处方和安装的医疗设备；在没有新处方的情况下，它们绝不应该被另一种镜片类型替代，因为所有的软性隐形眼镜都不是一样的。替代镜片可能具有在视力、眼部健康、舒适度和美容外观方面导致不良后果的特性，