Do scleral lenses hurt?

Why a big lens can feel better than a small one

The clear dome at the front of your eye, the cornea, is packed with nerves. It is one of the most densely innervated and sensitive tissues in the body.^[1] That’s why an eyelash or a speck of dust on it feels so dramatic.

Smaller hard contact lenses sit right on the cornea. A scleral lens is designed differently. It arches over the whole cornea without touching it and lands on the white of the eye, which is far less sensitive. The space between the lens and your cornea is filled with saline, so your cornea sits under a layer of fluid all day rather than under the lens.

That design is the reason the size isn’t the problem it looks like. The large diameter is what lets the lens reach past the sensitive part of your eye.

Feeling the lens versus pain

These are not the same, and it helps to know the difference.

Awareness is noticing the lens is there. You might feel the edge when you look far to one side, or feel the lids moving over it. Many people notice this most in the first days of wear.

Discomfort or pain is something more: a sharp or scratchy feeling, burning, a sore spot, or pressure that builds as the day goes on. Redness around the edge of the lens by evening is another sign worth reporting.

Your fitter is the right person to tell you what to expect with your eyes and your lenses. If you’re not sure which one you’re feeling, describe it to them rather than guessing.

What the research shows

Comfort problems are real for some people, and it’s better to know that going in.

• In a year-long study of 95 wearers, 27% stopped wearing their lenses during the year. Discomfort was the second most common reason, given by 19% of those who stopped. Handling was the most common, at 35% of those who stopped.^[2]
• In a study of 120 veterans fitted at one medical center, 55.0% had some difficulty with wear. The most common was ocular irritation, reported by 20.0% of all patients.^[3]
• Discomfort can often be fixed by changing the lens. In a study of one practitioner’s first 156 scleral fittings, about 10% of patients in each group needed a new lens ordered because of discomfort, even though the fit looked satisfactory. Most of those changes were made to the part of the lens that rests on the eye, and the authors report that comfort improved.^[4]

These are single-center studies with their own patient groups, so they can’t tell you what your experience will be. What they do show is that discomfort is a known, common issue, and that fitters have ways to change it.

Common causes of discomfort

Uncomfortable right after it goes in. This often points to a bubble under the lens or something on it. Take the lens out, check it for debris or chips, refill it to the brim with fresh preservative-free saline, and reinsert. The three checks after every insertion (light, vision, comfort) are covered in how to insert a scleral lens.

Pressure that builds, or a red ring by evening. This can mean the lens is resting too tightly on the white of the eye. Your fitter can change the landing zone, the part of the lens that touches the eye, so it follows the shape of your eye more closely. See redness around the lens edge.

Irritation from the wrong products. Only sterile, preservative-free saline belongs inside the lens. Preservatives such as benzalkonium chloride, common in multi-dose eye products, can damage the cells on the surface of the eye.^[5] Don’t switch saline, cleaners, or drops without asking your fitter.

A lens that’s aging. Scratches, chips, and film that cleaning won’t remove can make a lens less comfortable over time. Hold each lens up to the light before you put it in, and mention changes at your follow-up.

Dryness or a gritty feeling later in the day. This can come from the fit, from the tear film over the lens, or from an underlying dry eye condition. Your fitter can look at which one it is.

When discomfort means the fit needs changing

Tell your fitter, at your follow-up or sooner, if:

• the lens is uncomfortable the moment it goes in, even after you refill and reinsert
• you get pressure, soreness, or a red ring around the lens most days
• one eye is consistently less comfortable than the other
• comfort gets worse as the weeks go on rather than better
• you’re cutting your wearing time short because of how the lens feels

Be specific. “My eyes hurt sometimes” is hard to act on. “After about six hours, my right eye gets a sharp feeling at the outer corner that lasts until I take the lens out” gives your fitter something to work with. Saying “it’s fine” during a fitting when it isn’t only makes it harder to get the lens right.