Contact lenses are marked left and right
In general, standard soft lenses are not marked to indicate whether they are left or right. This is mainly because these types contact lenses hug the eyeball the same on both sides. If you use prescription contact lenses, it is possible that each eye may have a different correction. The left and right lens may feel differently or need to flipped depending on the lens type.
It is important that those who wear speciality contact lenses establish a regular routine to ensure the correct lens is put in the right ocular. This can be as simple as always putting the right contact lens in the top of your contact lens case and ensuring that you start with the right eye every time you put on your contact lenses. Additionally, some custom soft and scleral contact lenses come with diagnostic markings which help you to identify the correct orientation of the lens. A “left-side” scleral is often marked by two dots, while a “right-side” lens may be tinted blue.
If you wear colored contact lenses, it is also important to consider the shape and colour of your pupil. If you have two contacts that are similar in colour, this will make it easier to tell them apart. If you wear prescription contact lenses, you will most likely find your prescription on the box. This will include the base curve, diameter, power (or sphere) and then additional figures for Cylinder and Axis (if you have astigmatism) and an Addition and Dominant figure for presbyopia correction.