The pupillary distance is measured from the center of one pupil to the other. The focal point of the lens and the pupil centers of a person should coincide at a point to enable perfect vision. In instances where the pupillary distance is not measured accurately, people may experience blurry vision or other issues with the eye. The average pupillary distance for adults ranges from 50mm to 75mm and for children, 40mm to 60 mm. The female and male pupillary distances may differ. What are the pupils? The pupils are round structures at the center of the eye, which is black, and are, enclosed in the iris. Together with iris, pupil controls the amount of light entering the eye by expanding and contracting accordingly. Without accurately determining the pupillary distance, your eye doctor will not be able to prescribe you the correct pair of lenses. How do we measure Pupil to Pupil distance? The pupil to pupil distance is measured as either binocular PD or monocular PD. Binocular pupillary distance: In binocular PD method, the Optometrist/eye doctor will measure the pupil to pupil distance from the center of one pupil to the other. Monocular pupillary distance: In monocular PD method, your doctor will measure the distance from both centers of the pupil to the bridge of the nose in a straight line. This method is more precise since there are chances of either of both pupils to be not exactly equidistant from the bridge of the nose. Pupil to pupil distance traditionally is measured by the doctor using an apparatus known as pupilometer. It is usually done by your doctor during an eye examination using a PD ruler or corneal reflex pupilometer. It can be a great hindrance to going visit the eye doctor, every time one has to buy a new pair of eyeglasses. There are methods to measure the pupil to pupil distance on one’s own like using a millimetre ruler, or by finding out the exact point in an old eyeglass where you achieve clear vision. But these measurements are not accurate because of human error and can be tedious too. One cannot rely on these methods to buy eyeglasses if especially the person needs a progressive lens. In the case of progressive and bifocal lenses, the measurement of PD is highly critical for perfect vision. Nowadays, we have newer technologies to measure the pupil to pupil distance without going to the doctor. This is where www.pupilsdistance.com comes into the picture. www.pupilsdistance.com allows you to measure the pupillary distance by merely taking a photograph of your face and uploading it in the website. Both binocular PD and monocular PD values can be obtained. www.pupilsdistance.com uses software to measure the PD. People can use our software to obtain accurate PD values online on their own, as it eliminates human error. For buying eyeglasses online, be it reading glasses, progressive lenses or bifocal lenses, www.pupilsdistance.com can help you get your pupil to pupil distance with precision. Follow the instructions carefully, given in the website www.pupilsdistance.com to measure your pupillary distance, hassle-free.