眼图（英语：eye pattern）是电信系统的一种示波器显示，显示接收器上的数字信号，而以数据速度来触发水平的更新，在许多不同的编码系统下，眼图看来会像几个并排在一起的眼睛，故此得名。眼图会将特定时间内所有可能的变化都重叠在一个屏幕上，是在基频方波调制系统中，评估信道杂讯及符码间干扰的实验工具。

借由分析眼图可以看出许多系统的性能和问题，例如信号太长或太短、和时脉的同步不佳、信号电压太高或太低、太多杂讯、变化太慢、或是有过冲或下冲（undershoot），都可以在眼图上看出。若眼图的「眼睛」部份越大，表示信号失真的幅度越小，若因杂讯或是符码间干扰造成的信号失真，会使眼图的「眼睛」部份变小。

In telecommunication, an eye pattern, also known as an eye diagram, is an oscilloscope display in which a digital signal from a receiver is repetitively sampled and applied to the vertical input, while the data rate is used to trigger the horizontal sweep. It is so called because, for several types of coding, the pattern looks like a series of eyes between a pair of rails. It is an experimental tool for the evaluation of the combined effects of channel noise and intersymbol interference on the performance of a baseband pulse-transmission system. It is the synchronised superposition of all possible realisations of the signal of interest viewed within a particular signalling interval.